1, bring 200 kilometers of water into the city. This task was handed over to two construction teams, A and B, with a construction period of 50 days. After 30 days of cooperation between the two teams, team B had to leave for 10 days because of other tasks, so team A accelerated its speed and repaired 0.6 kilometers more every day. In order to ensure the construction period, team B 10 will come back in 0 days. Q: How many kilometers did Team A and Team B originally plan to build?

Solution: Let's assume that the original speeds of Party A and Party B are A km and B km per day respectively.

According to the meaning of the question

(a+b)×50=200( 1)

10×(a+0.6)+40a+30b+ 10×(b+0.4)= 200(2)

simplify

a+b=4(3)

a+0.6+4a+3b+b+0.4=20

5a+4b= 19(4)

(4)-(3)×4

A =19-4× 4 = 3km.

B = 4-3 = 1 km

A repairs 3 kilometers every day, and B repairs 1 kilometer every day.

A It was originally planned to build 3× 50 = 150km.

B 1× 50 = 50km as originally planned.

2. Xiaohua bought four mechanical pencil and two pens, and paid 14 yuan; Xiaolan bought the same 1 mechanical pencil and two pens, and paid 1 1 yuan. Find the unit price of mechanical pencil and pen.

Solution: Suppose mechanical pencil has a pen with X yuan and a pen with Y yuan.

4X+2Y= 14

X+2Y= 1 1

The solution is X= 1.

Y=5

In mechanical pencil, the unit price is 1 yuan.

Pen unit price 5 yuan

3. According to statistics, in 2009, the profit rate of commercial housing sold by builders in a certain area was 25%.

(1) What is the cost of a commercial house with a total selling price of 600,000 yuan in this region in 2009?

(2) In the first quarter of 20 1 0, the price per square meter of commercial housing in this area increased by 2 yuan, and the cost per square meter only increased by1yuan, so the area of commercial housing that can be purchased for 600,000 yuan decreased by 20 square meters compared with 2009, and the profit rate of builders reached one third, thus seeking the profit per square meter of commercial housing sold by builders in this area in 20 10.

Solution: (1) Cost = 600/(1+25%) = 480,000 yuan.

(2) In 2000, we set the price at 2,065,438+600,000 yuan to buy B square meters.

Cost of commercial housing in 20 10 year = 60/(1+1/3) = 450,000.

60/b-2a=60/(b+20)( 1)

45/b-a=48/(b+20)(2)

(2)×2-( 1)

30/b=36/(b+20)

5b+ 100=6b

B= 100 m2

The house price per square meter in 20 10 year =600000/ 100=6000 yuan.

Profit = 6000-6000/(1+1/3) =1500 yuan.

4. A store sold several pieces of A-type electrical appliances at the original price (cost+profit) in the first quarter, and each piece earned an average profit of 25%. In the second quarter, due to a slight increase in profit, the number of pieces sold by A Electric Appliance was only 5/6 of that in the first quarter, but the total profit was the same as that in the first quarter.

(1) What is the average profit per piece of Class A electrical appliances sold by this counter in the second quarter?

(2) In the third quarter, the counter sold 90% of the price in the first quarter. Therefore, the number of pieces sold increased by 65,438+0.5 times compared with the first quarter. What percentage is the profit of Class A household appliances sold in the third quarter higher than that of Class A household appliances sold in the first quarter?

Solution: (1) Let the cost be A, the number of pieces sold be B, and the profit rate in the second quarter be C.

Then profit =a×25%= 1/4a.

In the second quarter, 5/6b electrical appliances were sold.

Total profit in the first quarter = 1/4ab

Profit in the second quarter =ac×5/6b=5/6abc

According to the meaning of the question

1/4ab=5/6abc

c= 1/4×6/5

c=3/ 10=30%

(2) Pricing in the first quarter =a( 1+25%)=5/4a.

Pricing in the third quarter =5/4a×90%=9/8a

Sold (1.5+ 1)b=2.5b pieces in the third quarter.

Total profit in the third quarter =9/8a×2.5b-2.5ab=5/ 16ab.

Total profit growth in the third quarter (5/16ab-1/4ab)/(kloc-0//4ab) = (116)/(1/4) = 0.25.

5. Put some chickens in some cages. If there are four chickens in each cage, there is no cage for one chicken; If you put five chickens in each cage, there is only one cage without chickens. So, how many chickens and cages are there?

Suppose there are x chickens and y cages.

4y+ 1=x

5(y- 1)=x

Get x=25, y=6.

6. Make tin cans with tin foil. Each tinplate can be made into 25 boxes or 40 boxes. A box body and two box bottoms can be made into a set of cans. There are 36 iron sheets. How many pieces can I use to make the box and the bottom just match?

Analysis: Because there are always 36 iron boxes, x+y=36. Formula; The number of sheets made in the box+the number of sheets made at the bottom of the box = the total number of sheets made in cans * * * 36. The equation (1) is obtained. Because now a box body and two box bottoms are made into a set of cans, so; Number of boxes *2= number of box bottoms. This will make them equal. Equation (2)2* 16x=40y is obtained.

x+y=36 ( 1)

2* 16x=40y (2)

36-y=x (3) from ( 1)

Substituting (3) into (2) to obtain;

32(36-y)=40y

y= 16

If y= 16 is substituted (1), then x=20.

So; x=20

y= 16

Answer: Use 20 sheets as the box, and 16 as the bottom.

7. Now the total age of parents is six times that of children; Two years ago, the sum of parents' age and children's age was 10 times of children's age; The combined age of parents is three times that of children. Q: * * * When will the baby be born?

Solution:

The sum of parents' ages is X, the sum of children's ages is Y, and there are n children.

X=6Y

(X-4)= 10(Y-n*2)

6Y-4= 10Y-20N

4Y=20N-4

Y=5N- 1

(X+ 12)=3(Y+n*6)

6Y+ 12=3Y+ 18N

3Y= 18N- 12

Y=6N-4

6N-4=5N- 1

N=3

I have three children.

8. Party A and Party B set out from A and B at the same time, and the place where they first met was 50 kilometers away from the midpoint. After arriving at B and A, Party A and Party B immediately turned around and walked back. So, Party A and Party B met for the second time at a distance of A 100 meters to find the distance between A and B..

Two people, A and B, set out from A to B, A can't, B rides a bike. If a walks 6 kilometers, they will arrive at b at the same time after 45 minutes from b; If A takes the poem of 1 first, and B catches up with A half an hour after departure, find the distance between A and B. ..

Let the speed of a be a km/h and the speed of b be b km/h.

45 minutes =3/4 hours

6+3/4a=3/4b

a=(b-a)x 1/2

simplify

b-a=8( 1)

3a=b(2)

( 1)+(2)

2a=8

A=4 km/h

B = 3x4 =12km/h

AB distance = 12x 3/4 = 9 km.

9. The factory is connected with A and B by road and railway. The factory bought a batch of raw materials with a price of 65,438+0,000 yuan a ton from Party A and transported them back to the factory, and made products with a price of 8,000 yuan a ton to Party B. It is known that the road freight rate is 1.5 yuan/(ton km), and the railway freight rate is 1.2 yuan/(ton km). There are two kinds of transportation. What is the sales amount of this batch of products relative to the sum of raw material expenses and transportation expenses?

10, Dong Zhang went to the department store to buy two types of envelopes, 30 of which were * * *, of which 1 yuan 50 cents was used to buy type A envelopes and 1 yuan 50 cents was used to buy type B envelopes, and each type B envelope was 2 points cheaper than type A envelopes. What is the unit price of these two kinds of envelopes?

Solution: If the unit price of type A envelope is A, the unit price of type B envelope is a-2.

If you buy a B-type A envelope, you will buy a 30-b-type B envelope.

1 yuan.50 = 150.

ab= 150( 1)

(a-2)(30-b)= 150(2)

By (2)

30a-60-ab+2b= 150

Substitution (1)

30a- 150+2b=2 10

30a+2b=360

15a+b= 180

b= 180- 15a

Replace (1)

a( 180- 15a)= 150

Answer? - 12a+ 10=0

(a-6)？ =36- 10

a-6= √26

a=6 √26

A 1≈ 1 1 min, then the b-type envelope 1 1-2=9 points.

A2≈0.9, then 0.9-2=- 1. 1 of the type B envelope is irrelevant, so it is discarded.

The unit price of type A is 1 1, and that of type B is 9.

1 1. It is known that a railway bridge is 1000 meters long and a train passes by. It takes 1 minute for the train to get on the bridge from the start point to the end point, and the whole train will get on the bridge completely for 40 seconds. What about the speed and length of the train?

Let the train speed be one meter per second and the car body length be b meters.

1 min =60 seconds

60a= 1000+b

40a= 1000-b

100a=2000

A = 20m m/s

b=60x20- 1000

B=200 meters

It is 200 meters long. The vehicle speed is 20m/s.

12, Party A and Party B run on the circular road at a constant speed, if they start at the same time. Walk in opposite directions and meet every 2 minutes; If you go in the same direction, meet every 6 minutes. It is known that A runs faster than B. How many laps do A and B run per minute?

Solution: Let A run X laps per minute and B run Y laps per minute. According to the meaning of the question in the equation:

2X+2Y= 1

6X-6Y= 1

X = 1/3 and Y = 1/6 are obtained.

A: A runs 1/3 laps per minute, and B runs 1/6 laps per minute.

13, RMB 100 includes fifty cents, one yuan and two yuan, totaling 100 yuan. The sum of 50 points of 2 yuan is 75 yuan. How much is each kind in RMB?

Solution: Suppose there are five-corner A cards, one-dollar B cards and two-dollar 100-a-b cards.

According to the meaning of the question

0.5a+b+ 2×( 100-a-b)= 100( 1)

0.5a+2×( 100-a-b)=75(2)

(2) Replace (1)

B= 100-75=25 sheets.

Substitute (2)

0.5a+ 150-2a=75

75= 1.5a

a=50

So there are 50 50 yuan tickets, 25 Zhang Yiyuan tickets and 25 binary tickets.

14, both parties brought some money. If A gets half of B's money, then A * * * has 50. If B gets two-thirds of A's money, then B also has 50. Q: How much did Party A and Party B bring?

Solution: suppose a brings money a and b brings money B.

a+ 1/2b=50( 1)

b+2/3a=50(2)

simplify

2a+b= 100(3)

3b+2a= 150(4)

(4)-(3)

2b=50

B=25 yuan.

A=50-25/2=37.5 yuan

A brought 37.5 yuan, and B brought 25 yuan.

15. Both Party A and Party B have deposited several yuan in the bank. It is known that one quarter of Party A's deposit is equal to one fifth of Party B's deposit, and it is known that Party B has more deposits in 24 yuan than Party A. How much is each?

Solution: let a have a yuan and b yuan.

1/4a= 1/5b

b-a=24

solve

a=96

b= 120

16、

One-dimensional linear equation 100 example

1. The distance between the two stations is 275 kilometers. The local train goes from Station A to bilibili at a speed of 50 kilometers per hour. 1h later, the express train runs from bilibili to Station A at a speed of 75km/ h. How many hours after the local train leaves, will you meet the express train?

Set the local train to meet the express train in an hour.

50a+75(a- 1)=275

50a+75a-75=275

125a=350

A=2.8 hours

2. A car travels from place A to place B at a speed of 40 kilometers per hour. After 3 hours, due to the rain, the average speed was forced to drop 10km. The result arrived at B 45 minutes later than expected. Find the distance between a and b.

Set the original time to one hour.

45 minutes =3/4 hours

According to the meaning of the question

40a = 40×3+(40- 10)×(a-3+3/4)

40a= 120+30a-67.5

10a=52.5

A=5.25=5, 1/4 hours =2 1/4 hours.

So the distance between Party A and Party B is 40×2 1/4=2 10 km.

The locksmith class in a workshop is divided into two teams to watch the tree planting work. The number of people in Team A is twice that of Team B. If 16 people are transferred from Team A to Team B, the number of people left in Team A is three less than that of Team B. What about the original numbers of Team A and Team B?

Solution: Team B originally had A, while Team A had 2a.

Then according to the meaning of the question

2a- 16 = 1/2×(a+ 16)-3

4a-32=a+ 16-6

3a=42

a= 14

Then team B was originally 14, and team A was originally 14×2=28.

At present, team B 14+ 16=30 people, and team A = 28- 16= 12 people.

4. It is known that the profit of a store in March is 654.38+10,000 yuan, and the profit in May is1320,000 yuan. The month-on-month growth rate in May was 654.38+00 percentage points higher than that in April. Find the monthly growth rate in March.

Solution: Let April profit be X.

Then x * (1+10%) =13.2.

So x= 12.

Let the growth rate in March be y.

Then10 * (1+y) = X.

y=0.2=20%

So the growth rate in March was 20%

5. The school arranges dormitories for boarding students. If there are 7 people living in each dormitory, 6 people can't arrange it. If there are 8 people living in each dormitory, then there are only 4 people living in one dormitory, and there are 5 empty dormitories. How many people are there?

Solution: There is room A, with 7a+6 people in total.

7a+6=8(a-5- 1)+4

7a+6=8a-44

a=50

Someone =7×50+6=356 people

6. One kilogram of peanuts can fry 0.56 kilograms of peanut oil, so how much peanut oil can be fried in 280 kilograms?

Proportional solution

Suppose you can fry one kilogram of peanut oil.

1:0.56=280:a

A = 280× 0.56 = 156.8kg

Complete formula: 280 ÷1× 0.56 =156.8kg.

7. A batch of books are distributed to Class 1 10 and Class 2 15. How many books have been distributed in both classes now?

Solution: Let's assume that there are a total of books.

Class number =a/ 10

Number of Class Two =a/ 15

Then they are evenly divided into two categories, each of which is a/(a/10+a/15) =10×15/(10+15) =/kloc.

8. The tree planting team of June 1st Squadron went to plant trees. If everyone plants five trees, there are still 65,438+04 seedlings left. If each race has seven trees, there will be six fewer seedlings. How many people are there in this team? A * *, how many seedlings?

Solution: There is one person.

5a+ 14=7a-6

2a=20

a= 10

A * * * has 10 people.

There are 5× 10+ 14=64 saplings.

9. A barrel of oil weighs 50 kilograms. Half of the soybean oil poured out for the first time was less than 4 kilograms, and the remaining three-quarters were two and two-thirds kilograms more for the second time. At this time, the barrel filled with oil weighs one third of a kilogram. How much oil was there in the original barrel?

Solution: Let the oil weigh one kilogram.

Then the barrel weighs 50-a kilograms.

Pour out 1/2a-4kg for the first time, leaving 1/2a+4kg.

Pour out 3/4× (1/2a+4)+8/3 = 3/8a+17/3kg for the second time, leaving1/2a+4-3/8a-17/3 =/kloc.

According to the meaning of the question

1/8a-5/3+50-a= 1/3

48=7/8a

A = 384/7kg

There used to be 384/7kg of oil.

10, use a bundle of 96m cloth to make clothes for the students in Class 1, Grade 6, 15 use 33m cloth. According to this calculation, which class is the most suitable for these fabrics to make school uniforms? (1 class 42, class 2 43, class 3 45)

Give person a 96 meters.

According to the meaning of the question

96:a=33: 15

33a=96× 15

A about 43.6

So it is suitable for Class 2, with a surplus, but not much. It is not enough to do it for Class Three.

1 1, a fraction. If the numerator adds 123 and the denominator subtracts 163, the new fraction is 3/4; If the numerator adds 73 and the denominator adds 37, then the new score is reduced to 1/2, and the original score is found.

Solution: Add 123 to the original fractional numerator and subtract 163 from the denominator to get 3a/4a.

According to the meaning of the question

(3a- 123+73)/(4a+ 163+37)= 1/2

6a- 100=4a+200

2a=300

a= 150

Then the original score = (3×150-123)/(4×150+163) = 327/763.

100 examples of solving application problems of quadratic equation in one variable

1. A clothing store sells 50 yuan underwear from 30 yuan at an average price of 300 pieces per month. After the trial sale, it is found that the price of each underwear will increase by 10 yuan, and its sales will decrease by 10. In order to achieve a daily sales profit of 8700 yuan, if you are a seller, how would you arrange the purchase?

Solution: If the price of 10a is increased on the basis of 59 yuan, 10a will be sold less.

According to the meaning of the question

(50+ 10a-30)×(300- 10a)= 8700

(20+ 10a)×(30-a)=870

(a+2)(a-30)=-87

Answer? -28a+27=0

(a- 1)(a-27)=0

A= 1 or a=27

When a= 1, the price increases by 10 yuan, and 300- 10× 1=290 pieces are sold.

When a=27, the price will increase by 27× 10=270 yuan, and 300- 10×27=30 pieces will be sold (this price is unrealistic).

Belonging to theoretical calculation

2. A company produces a certain commodity. The cost of each product is 3 yuan and the price is 4 yuan. The annual sales volume is 654.38+ten thousand pieces. In order to cope with the global economic crisis in 2009, the company is going to spend some money on advertising. According to experience, the annual advertising investment is X (10,000 yuan), and the product sales will be Y times of the original, while

y=-x？ /10+7/10x+7/10IF: annual profit = total sales-cost-advertising fee.

(1) Can the company's annual profit reach 1.5 million? Can it reach 1.6 million?

(2) Can the company's annual profit reach 6.5438+0.7 million? If yes, please calculate how much the advertisement should be at this time. If not; Please provide a justification for the answer.

Solution: Suppose the annual profit is one million yuan,

a=4× 10y-3× 10y-x

=40y-30y-x= 10y-x

= 10×(-x？ / 10+7/ 10x+7/ 10)-x

=-x？ +7x+7x

=-x？ +6x+7

When a= 15

-x？ +6x+7= 15

x？ -6x+8=0

(x-2)(x-4)=0

X=2 or 4

When the advertising fee is 20,000 yuan or 40,000 yuan, the profit will reach 6.5438+0.5 million yuan.

When a= 16

-x？ +6x+7= 16

x？ -6x+9=0

(x-3)？ =0

x 1=x2=3

When the advertising fee is 30,000 yuan, the profit will reach 6.5438+0.6 million yuan.

When a= 17

-x？ +6x+7= 17

x？ -6x+ 10=0

Discriminant = 36-40 =-4

So the profit can't reach 1.7 million.

3. Several people in an interest group send each other a greeting card during the New Year. It is known that the whole group has issued a 132 card. Please find out the number of people in this group.

Solution: Suppose there is a person in this group.

According to the meaning of the question

a×(a- 1)= 132

Answer? -a- 132=0

(a- 12)(a+ 1 1)= 0

A= 12 or a=- 1 1 (omitted)

There were 12 people, and each person received12-1=11card.

4. Party A and Party B complete a project in 6 days, and it is known that it will take 5 days for Party A to do it alone. How many days does it take for Party A to complete it alone?

Solution: Suppose it takes X days for B to finish it alone.

6× 1/x+6× 1/(x+5)= 1

6x+30+6x=x？ +5 times

x？ -7x-30=0

(x- 10)(x+3)=0

X= 10 or x=-3 (omitted)

B it takes 10 days to complete it alone.

A it takes 10+5= 15 days to complete it alone.

5. A village plans to build a rectangular vegetable greenhouse as shown in the figure, and the length-width ratio is required to be 2: 1. In the greenhouse, an open space with a width of 3M is reserved along the front inner wall, and passages with a width of 1M are reserved on the other three inner walls. When the length and width of rectangular greenhouse are respectively what, the vegetable planting area is 288m2?

Solution: If the width is one meter, then the length is 2 meters.

According to the meaning of the question

(2a-3- 1)(a- 1- 1)= 288

(2a-4)(a-2)=288

(a-2)？ = 144

a-2= 12

a=2 12

A= 14 or a=- 10 (irrelevant, omitted)

Therefore, when the width is 14 m and the length is 28 m, the area of vegetable planting area is 288 square meters.

6. A village plans to build a channel with an isosceles trapezoid cross section with an area of 10.5m? The upper bottom surface is 3m wider and 2m deeper than the lower bottom surface. How wide should the upper bottom be dug?

Solution: If the upper bottom is one meter, the lower bottom is a-3 meters, and the depth is a-2 meters.

According to the meaning of the question

(a+a-3)×(a-2)/2= 10.5

(2a-3)(a-2)=2 1

2a？ -5a- 15=0

(2a+3)(a-5)=0

A=5 or a=-2/3 (irrelevant, omitted)

So the upper bottom is 5 meters.

7. A shop sells a batch of shirts. If each shirt is profitable in 40 yuan, it can sell 20 shirts a day. In order to reduce inventory and increase profits as soon as possible, the mall decided to cut prices. If you reduce each shirt by 1 yuan, you can sell 2 more shirts a day on average. Q: When each shirt is reduced, the average daily profit will be 1200 yuan?

Solution: Suppose the price is reduced by one yuan, then a lot of 2a ones are sold.

(40-a)×(20+2a)= 1200

800-20a+80a-2a？ = 1200

Answer? -30a+200=0

(a- 10)(a-20)=0

A= 10 or a=20.

That is to say, it is enough to reduce the price by 10 yuan or 20 yuan.

8. The average monthly output growth rate of a factory in the first quarter is X, the output value in January is A yuan, and the output value in March becomes1.21a. What is the value of x?

Solution: let the increment of yield be x.

a( 1+x)？ = 1.2 1a

( 1+x)？ = 1. 1

1+x= 1. 1 or 1+x=- 1. 1.

X=0. 1 or -2. 1 irrelevant, omitted.

Growth rate = 10%

9. To manufacture a product, because the cost is reduced by 36% twice in a row, what is the average percentage of cost reduction each time?

Solution: let the cost be a and reduce x every time.

a( 1-x)？ =a×( 1-36%)

( 1-x)？ =0.64

1-x=0.8 or 1-x=-0.8.

X=0.2 or 1.8 (irrelevant, omitted)

Reduce by 20%

10. A store buys a batch of goods at the price of 2 1 yuan each. Commodities can be priced by themselves. If each product is one yuan, you can sell (350- 10a) pieces. However, the price bureau limits the profit of each product to no more than 20%. How many pieces does the store need to purchase to make a profit in 400 yuan? What's the price of each piece?

Solution: according to the meaning of the problem

(a-2 1)(350- 10a)=400

350a-7350- 10a？ +2 10a=400

Answer? -56a+775=0

(a-25)(a-3 1)=0

A=25 or a=3 1

Because the profit does not exceed 20%, a is at most 2 1×( 1+20%)=25.2.

So a=3 1 is irrelevant, so it is omitted.

So a=25

The price is 25 yuan, and the stock is 350- 10×25= 100.

1 1. If the number of people in a travel agency does not exceed 25, the per capita cost is 1000 yuan. If there are more than 25 people, the per capita travel expenses will be reduced in 20 yuan, but the per capita expenses shall not be lower than the charging standard in 700 yuan. The employees of a certain unit paid 27,000 yuan for a tour. How many people participated in the tour?

Solution: First, judge.

There are more than 25 people in this unit.

Because if there are 25 people, then the amount of money used is 25 ×1000 = 25,000 yuan.

So more than 25 people

Suppose one person is added, and the per capita cost is 1000-20a-20 yuan.

( 1000-20a)×(25+a)=27000

25000-500a+ 1000a-20a？ =27000

20a？ -500 Amps +2000=0

Answer? -25a+ 100=0

(a-5)(a-20)=0

A=5 or 20

When a=20, the per capita cost = 1000-20× 20 = 600.

So a=20 doesn't matter, so I gave up.

So 25+5=30 people travel.

12. Use a 20-meter-long iron wire to form a rectangle with an area of 25 square meters. What is the length of this rectangle?

Solution: If the length is x meters and the width is 20/2-x= 10-x meters.

According to the meaning of the question

( 10-x)x=25

x？ - 10x+25=0

(x-5)？ =0

x 1=x2=5

So the length = width = 5m of a rectangle is a square.

13, a school-run factory 10 produced 200 sets of A products. By improving the production technology, the total output in February and March increased by the same percentage point compared with the previous month, so the total output in the first quarter reached 1400 units. What is the percentage?

Solution: let this percentage be a.

200+200( 1+a)+200( 1+a)？ = 1400

Let 1+a=t

t？ +t-6=0

(t-2)(t+3)=0

T=2 or t=-3 (truncation)

So 1+a=2.

a= 1= 100%

14, with two numbers. Their sum is 13, and their product is -48. What are these two numbers?

Solution: Let one number be a and the other number be13-a.

a( 13-a)=-48

Answer? - 13a-48=0

(a- 16)(a+3)=0

A=-3 or a= 16

When a=-3, another number is 16.

When a= 16, another number is -3.

Please refer to these application questions and practice as appropriate.

Ask: Beijing Normal University Edition Ninth Grade Mathematics Teaching Plan Complete Works: doc.dangzhi./list/c-66-t-1.

Seek the preface of the first volume of ninth grade mathematics of Beijing Normal University Edition

Chapter 65438 +0 proof (2)

Can you prove them?

Congruent triangles's Judgment (1)

Congruent triangles's Judgment (2)

Congruent triangles's Judgment (3)

Properties of isosceles triangle

Determination of isosceles triangle

Right triangle in the second quarter

pythagorean theorem

Inverse theorem of Pythagorean quantization

Determination of congruence of right triangle

Perpendicular bisector of section 3 line segment

Fourth quarter angle bisector

Chapter II Quadratic Equation in One Variable

How wide is the lace moon in section 1?

Section 2 Matching Methods

Section 3 Formula Method

The fourth quarter factorization method

Why is section 5 0.6 18?

Chapter III Proof (3)

1 parallelogram section

Parallelogram (1)

Parallelogram (2)

Special parallelogram in the second quarter

Special parallelogram (1)

Special parallelogram (2)

Chapter 4 Views and Forecast

Chapter V Inverse Proportional Function

Chapter 6 Frequency and Probability

Beijing Normal University Edition Nine Grade Mathematics Volume I P94 Example 2 Answer. This kind of problem seems to be more difficult.

The problem of verification is like crossing a river, you must know the direction to go right.

What are the sufficient conditions for proving the conclusion from verification? Then pick out the conditions (relationships) that you can prove.

The specific answer will be sent to you when I am free.

20 16 Tianfu Frontier Ninth Grade Mathematics Volume I Beijing Normal University Edition Answer for help There should be no answer here. You can ask your teacher or classmates and try to do it yourself. If not, let your classmates tell you about it, which is helpful for your study. The answer can only be solved temporarily.

You still have to do your homework by yourself. Asking for answers is a bad habit. Do your own homework, so that you can have a sense of accomplishment. Who can give you the answer if you don't even send out the questions? Ask teachers and classmates more, and your grades can be improved.

The fourth question on page P62.3.P63.4 P64, the first volume of ninth grade mathematics of Beijing Normal University, assumes that the △ABO area is S 1, the △ABP area is S2, and the △ACP area is S3.

s 1+S2+S3 =( 1+a)* 14/2

S 1=a*a/2

S3= 1*( 14-a)/2

S2 =( 1+a)* 14/2-a * a/2- 1 *( 14-a)/2 =(-a * a+ 15 * a)/2

that is

(-a*a+ 15*a)/2= 18

Solve the equation and get

A = 12 or A = 3.

Who has the teaching video of the first volume of ninth grade mathematics published by Beijing Normal University? Potatoes are available, but I downloaded the People's Education Edition and some Beijing Normal University editions. Ask the teacher.

How can I give you the ninth grade math textbook published by Beijing Normal University? .......

The ninth grade mathematics instruction training volume II Beijing Normal University Edition answer You go to Xue Hai and ask again, there is nothing to book.

Qiuxin Beijing Normal University Edition Ninth Grade Mathematics Volume I PPT Free Website11999, New Curriculum Standard Courseware Network