After 80, Zhang Qiang got married, and after 50, she was an aunt.
1, after 80, Zhang Qiang got married. Aunt after 50: Give me a junior high school math problem? Thank you? 1. Solve equation 6x+ 1=-4, and the correct shift term is ().
A.6x=4- 1B。 -6x =-4- 1c . 6x = 1+4d . 6x =-4- 1
2. Solve the equation -3x+5=2x- 1, and the shift term is correct ().
A.3x-2x=- 1+5B。 -3x-2x = 5- 1c . 3x-2x =- 1-5D。 -3x-2x=- 1-5
3. The solution of equation 4(2-x)-4(x)=60 is ().
-d-7
4. If 3x+2=8, then 6x+ 1= ()
5. If the solution of equation 6x+3a=22 is the same as that of equation 3x+5= 1 1, then a= ().
-D ...
6. If and? 2 is a similar term, then n= ()
American Broadcasting Company Inc (ABC)
7.y 1= known. If y 1+y2=20, then x= ().
A.-.-
8. If the solution of equation 5x=-3x+k is-1, then k=.
9. If the solutions of equation 3x+2a= 12 and equation 3x-4=2 are the same, then a=
10. If the sum of three consecutive odd numbers is not 2 1, their product is
1 1. If it is not equal to 3m-2, the value of m cannot be.
12. If 2? 3-2k+2k=4 1 is a linear equation about x, then x=
13. If x=0 is the solution of the equation -a=+3, then the value of the algebraic expression is -a2+2.
14. Solve the following equation
( 1)3x-7+4x=6x-2(2)
(3)(x+ 1)-2(x- 1)= 1-3x(4)2(x-2)-6(x- 1)= 3( 1-x)
8，k=-89，a=， 1 1，m≦，x= 13，29
14，( 1)x = 5(2)x =-22(3)x =- 1(4)x =-6
One-dimensional linear equation 1 If (x+y): (x-y) = 3: 1, then x: y = ().
a、3∶ 1B、2∶ 1C、 1∶ 1D、 1∶2
2. If the solution of equation -2x+m=-3 is 3, then the value of m is ().
a、6B、-6C、D、- 18
3. In the equation 6x+ 1= 1, 2x=, 7x- 1=x- 1, 5x=2-x, the number of solving equations is ().
a， 1 b，2 c，3 d，4
4. According to the quantitative relationship of "3 times a and the difference between -4 equals 9", equation () can be obtained.
a 、|3a-(-4)|=9B 、|3a-4|=9
c、3|a|-|-4|=9D、3a-|-4|=9
5. If the solution of the equation =4(x- 1) about x is x=3, then the value of a is ().
A, 2B, Brazil, Brazil -2
Answer and analysis
Answer: 1, B2, A3, B4, D5, C 1. Analysis: This question examines the identity deformation of the equation.
From (x+y)∩(x-y)= 3∶ 1, we know that x+y=3(x-y), which is simplified as: x+y=3x-3y.
2x-4y=0, that is, x=2y and x∶y=2∶ 1.
2. Analysis: ∫3 is the solution of equation -2x+m=-3,
∴-2×3+m=-3，
That is -6+m =-3,
∴ m =-3+6, the basic properties of-accommodation equation, 1
∴ m = 6, the basic properties of-accommodation to Equation 2
Choose a.
3. Analysis: the solution of 6x+ 1= 1 is 0, that of 2x= 0, that of 7x- 1=x- 1 is 0, and that of 5x=2-x is 0.
4. Omit.
5. Analysis: Because x=3 is the solution of equation =4(x- 1), substituting x=3 into the equation will satisfy the equation.
I. Multivariable types
The application problem of the solution of multivariate linear equation refers to the application problem with many unknowns and many equality relations in the problem. As long as one of these unknowns is X, the other unknowns can be represented by an algebraic expression containing X according to the equality relation in the topic, and then a linear equation can be listed according to another equality relation.
Example 1: In order to save electricity in summer, air conditioners often take two measures: raising the set temperature and cleaning the equipment. At first, a hotel raised the set temperature of A and B air conditioners by 1℃. Results A air conditioner saves 27 degrees more electricity every day than B air conditioner. Then clean the equipment of air conditioner B, so that the total electricity saving of air conditioner B is 1. 1 times that of air conditioner A only when the temperature rises, while the regulated electricity of air conditioner A remains unchanged, so that the two air conditioners can save electricity every day. After the temperature is increased by 1℃, how many kWh can each air conditioner save every day?
Analysis: There are four unknowns in this question: the regulated electric quantity of air A after heating, air B after heating, air A after cleaning equipment and air B after cleaning equipment. The equations are as follows: a-a-b-a-b-a = 27, b-a-b =1.1× b-a-b-a = a-b-a+b = a-a-b-a-a-.
Solution: Suppose that only after the temperature increases by 1℃, the second air conditioner saves X degrees of electricity every day, and the first air conditioner saves electricity every day. According to the meaning of the question, a: Only when the temperature increases 1℃, the A-type air conditioner saves electricity every day, and the B-type air conditioner saves electricity every day.
Second, segmented.
The application of piecewise linear equations refers to a class of application problems with the same unknown quantity and different restrictions in different ranges. When solving this kind of problem, we must first determine the segmentation of the given data, and then solve it reasonably according to its segmentation.
Example 2: The price of bananas in a fruit wholesale market in Dongying in is as follows:
The number of bananas purchased
(kg) not exceeding
20 kg or more
But not more than 40 kilograms, more than 40 kilograms.
Price per kilogram 6 yuan 5 yuan 4 yuan
Zhang Qiang bought 50 kilograms of bananas twice (the second time was more than once), and * * * paid RMB. How many Jin of bananas did Zhang Qiang buy for the second time and the second time respectively?
Analysis: Because Zhang Qiang bought 50 kilograms of bananas twice (more than twice), the second time he bought more than 25 kilograms of bananas, each time less than 25 kilograms. Because 50 kilograms of bananas pay RMB * * *, the average price is 5.28 yuan, so the price of bananas purchased for the second time is 6 yuan/kg, which is less than 20 kilograms. The price of the second banana purchase may be 5 yuan or 4 yuan. We can discuss it in two situations. 1) When the first banana purchase quantity is less than 20kg and the second banana purchase quantity is more than 20kg but not more than 40kg, the second banana purchase quantity is x kg and the second banana purchase quantity is (50-x) kg.
6x+5(50 times) = 1
Solution: x = 14
50- 14 = 36 (kg)
2) When the first banana purchase amount is less than 20kg and the second banana purchase amount is more than 40kg, the second banana purchase amount is x kg and the second banana purchase amount is (50-x) kg.
How many homophones does Zhang Qiang have 6x+4 (50-x) =?
Solution: x = 32 (irrelevant)
Answer: I bought 14kg bananas for the first time and 36kg bananas for the second time.
Example 3: (Jingmen City, Hubei Province, in) participated in the insurance of an insurance company, and hospitalized patients enjoyed reimbursement by installments. The reimbursement rules formulated by insurance companies are as follows. If someone is reimbursed by the insurance company after hospitalization, then this person's living expenses are ().
Proportion of reimbursement for hospitalization expenses (yuan) (%)
No more than part 0 of the meta.
The part that exceeds 60 yuan
The part exceeding ~ yuan, yuan b, yuan c, yuan d, yuan
Solution: Let this person's hospitalization expenses be X yuan. According to the meaning of the question:
×60%+(x-)80%=
Solution: x =
So the answer to this question is D.
Third, the scheme type.
One-dimensional linear equations based on schemes often give two schemes to calculate the same unknown, and then the algebraic expressions representing the two schemes are combined with an equal sign to form a one-dimensional linear equation.
Example 4: Grade three students in a school in Quanzhou participate in practical activities. It was originally planned to rent a number of 30-seat buses, but there were still 15 people without seats.
(1) Assume that X 30-seat buses were originally planned to be rented, and the algebraic expression containing X represents the total number of third-grade students in the school;
(2) Now it is decided to rent a 40-seat bus, one less than the original planned 30-seat bus, and one of the rented 40-seat buses is not full and only takes 35 people. Please find out the total number of third-grade students in this school.
Analysis: There are two schemes to show the total number of students in Grade Three. The total number of students is+15, with 30 buses.
The total number of people is represented by the number of 40 buses: 40 (x-2)+35.
Solution: (1) The total number of junior three students in our school+15.
(2) From the meaning of the problem:
+ 15=40(x-2)+35
Solution: x = 6
+15 = 30× 6+ 15 = (person)
A: There are always * * * people in the third grade.
Fourth, the type of data processing
When dealing with linear equations with data to solve application problems, we often don't directly tell us some conditions, so we need to analyze the given data and get the data we need.
Example 5: (Haidian District, 2000) Application Problem Solution: In April 2000, China's railways increased speed for the fifth time. Assuming that the average speed of the second air-conditioned express train is 44 km/h higher than that before the speed increase, the train timetable before the speed increase is shown in the following table:
The start time and arrival time of the train in the driving interval last for the whole mileage.
A-B 2:: hour kilometer
Please fill in the accelerated train timetable according to the information provided by the topic and write out the calculation process.
The start time and arrival time of the train in the driving interval last for the whole mileage.
The start time and arrival time of the train in the 2: 00 km interval from A to B last the whole mileage.
A-B 2. Four hours and kilometers.
Analysis: According to the table 1, the train speed before the speed increase is ÷ 4 = 66 km/h, so as to get the speed after the speed increase, and then calculate the required value according to the data given in Table 2.
Solution: Assume that the running time of the train after speed increase is X hours.
After inspection, x=2.4 meets the requirements.
A: The arrival time is 4:24, which lasts 2.4 hours.
Example 6: (Zhejiang Province) It is understood that the price is determined by the method of "". It is known that the total mileage from Station A to Station H is 1 km, and the reference price for the whole journey is RMB. The following table shows the mileage from stations along the way to H station:
Station name ABCDEFGH
Mileage from each station to H station (unit: km)
For example, to determine the price from mile to mile to e station, the fare is (yuan).
(1) Find the price from station A to station F (the result is 1 yuan);
(2) Passenger Aunt Wang goes to her daughter's house by train. After getting on the bus for two stops, she asked the flight attendant with her hand, am I near the station? When the stewardess saw that Aunt Wang's ticket price was 66 yuan, she immediately said that the next stop was here. At which station does Aunt Wang get off? Write the solution process.
Solution: (1) solution 1: known.
The actual mileage from station A to station F is-=.
So the price from station A to station F is 0. 12=.72 yuan.
Solution: The price from station A to station F is (yuan).
(2) Let Aunt Wang's actual mileage be X kilometers.
The solution is x= (km).
According to the comparison table, the distance between Station D and Station G is kilometers, so Aunt Wang gets off at Station D or Station G. 。
Algebra chapter 6 ability self-test questions
One-dimensional linear inequality and one-dimensional linear inequality system
Junior high school mathematics website
fractional equation
(1) Fill in the blanks
The equation about y is _ _ _ _.
(2) Choose
a . x =-3； b . x≦-3；
C. all real numbers; D. no solution.
C. no solution; D. all real numbers
a . x = 0； B.x=0，x = 1；
C.x=0，x =- 1； D. the value of algebraic expression cannot be zero.
a . a = 5； b . a = 10；
c . a = 10； D.a= 15。
a . a =-2； b . a = 2；
c . a = 1； D.a=- 1。
A. all real numbers; All real numbers of b.x ≠ 7;
C. no solution; All real numbers of d. x≦- 1, 7.
a . a = 2； B.a only has 4;
C.a = 4 or 0; D. None of the above answers are correct.
a . a > 0； B.a > 0 and a ≠1;
C.a > 0 and a ≠ 0; D.a0。
(3) Solving equations
5 1. Party A and Party B set out from place A at the same time and walked 30 kilometers to place B. Party A walked more than Party B 1 km per hour, and as a result, Party A arrived earlier than Party B 1 hour. How many kilometers did they walk per hour?
http:// ..
The above has something to do with giving me a junior high school math problem? Thank you? Related content, is it about giving me 150 junior high school math problems? Thank you? Share. After reading 80, Zhang Qiang married an aunt after 50, I hope this can help everyone!