1.(2005? Ningde) Solve the equation: 2x+ 1=7.
2.
3.( 1) Solve the equation: 4-x = 3 (2-x);
(2) Solve the equation:
4. Solve the equation:
5. Solve the equation
( 1)4(x﹣ 1)﹣3(20﹣x)=5(x﹣2)；
(2)x﹣=2﹣.
6.( 1) Solve the equation: 3 (x-1) = 2x+3;
(2) Solve the equation: = x ﹣.
7.﹣( 1﹣2x)=(3x+ 1)
8. Solve the equation:
( 1)5(x﹣ 1)﹣2(x+ 1)=3(x﹣ 1)+x+ 1；
(2).
9. Solve the equation:
10. Solve the equation:
( 1)4x﹣3(4﹣x)=2；
(2)(x﹣ 1)=2﹣(x+2).
1 1. Calculation:
(1) calculation:
(2) Solve the equation:
12. Solve the equation:
13. Solve the equation:
( 1)
(2)
14. Solve the equation: (1) 5 (2x+1)-2 (2x-3) = 6.
(2)+2
(3)[3(x﹣)+]=5x﹣ 1
15. (Class A) Solve the equation: 5x-2 = 7x+8;
(Class B) Solving equations: (x-1)-(x+5) =-;
(class c) solving equations:
16. Solving equations
( 1)3(x+6)=9﹣5( 1﹣2x)
(2)
(3)
(4)
17. Solve the equation:
(1) Solve the equation: 4x-3 (5-x) = 13.
(2) Solving equation: x-3
18.( 1) Calculation: -42×+|-2 | 3× (-) 3
(2) Calculation: | 12 | 0.5 |÷2 |(| 3)2]
(3) Solving equation: 4x-3 (5-x) = 2;
(4) Solve the equation:
19.( 1) Calculation: (1-2-4) ×;
(2) Calculation:
(3) Solving the equation: 3x+3 = 2x+7;
(4) Solve the equation:
20. Solve the equation (1)-0.2 (x-5) =1;
(2).
2 1. Solve the equation: (x+3)-2 (x- 1) = 9-3x.
22.8x﹣3=9+5x.
5x+2(3x﹣7)=9﹣4(2+x).
.
.
23. Solve the following equation:
( 1)0.5x﹣0.7=5.2﹣ 1.3(x﹣ 1)；
(2)=﹣2.
24. Solve the equation:
( 1)﹣0.5+3x= 10；
②3x+8 = 2x+6；
(3)2x+3(x+ 1)=5﹣4(x﹣ 1)；
(4).
25. Solve the equation:
26. Solve the equation: (1)10x-12 = 5x+15; (Jing Rui)
(2)
Find 88 linear equation application problem 44 and simplify and evaluate a linear equation problem 20. Simplify and evaluate the problem 1 1, 3x' y-[2x' y-(2-x' z)-4x' z]-, where x =-2 and y =-3, z.
Original formula =3x'y-[2x'y-(2-x'z)-4x'z]-
=3x'y-2x'y+2-x'z+4x'z-
=x'y-+3x'z
When x = 2, y = 3 and z = 1
The original formula = 4 * (3)-2 * 3 *1+3 * 4 *1.
=- 12-6+ 12
=-6
2,3x+2y)+(4x+3y) where x = 5 and y+3.
Original formula =3X+2Y+4X+3Y=7X+5Y.
When x = 5 and y = 3.
Original formula =5*7+(-3)*5+20.
=35- 15+20
=40
3,2x-3 (2x-x)+(2y-y), where x = 1 and y = 2.
Solutions; Original formula =2x-3x+y
When x = 1 and y = 2.
The original formula =2* 1-3* 1+2.
=2-3+2
= 1
(5a 2-3b 2)+(a 2+b 2)-(5a 2+3b 2), where a =- 1 and b = 1.
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(- 1)^2-5* 1^2
= 1-5
=-4
5,2 (A2B+AB 2)-2 (A2B-1)-2AB 2-2, where a =-2 and b = 2.
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0,
6, a 2-ab+2b 2 = 3 Find the value of 2ab-2a 2-4b 2-7.
2ab-2a^2-4b^2-7
=2(ab-a^2-2b^2)-7
=-2(a^2-ab+2b^2)-7
=(-2)*3-7
=-6-7
=- 13
7. If a = 2x 2+3xy-2x-3, b =-x 2+xy+2, and the value of 3A+6B has nothing to do with X, find the value of y..
3a+6b=6x^2+9xy-6x-9-6x^2+6xy+ 12
= 15xy-6x+3
=x( 15y-6)+3
8, x+6x2-3 (x-2/3x2), where x=-2.
9x+6x？ -3(x-2/3x？ )
=9x+6x？ -3x+2x？
=8x？ +6 times
=8×(-2)? +6×(-2)
=32- 12
=20
9,1/4 (-4x2+2x-8)-(1/2x-1), where x= 1/2.
1/4(-4x？ +2x-8)-( 1/2x- 1)
=-x？ + 1/2x-2- 1/2x+ 1
=-x？ - 1
=-( 1/2)? - 1
=- 1/4- 1
=-5/4,
10, 3x' y-[2x' y-(2-x' z)-4x' z]-, where x =-2, y =-3, z = 1,
:3x'y-[2x'y-(2-x'z)-4x'z]-
=3x'y-2x'y+2-x'z+4x'z-
=x'y-+3x'z
=4*(-3)-2*3* 1+3*4* 1
=- 12-6+ 12
=-6
1 1, (5a 2-3b 2)+(a 2+b 2)-(5a 2+3b 2), where a =- 1 and b = 1.
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(- 1)^2-5* 1^2
= 1-5
=-4
12,2 (a2b+ab2)-2 (a2b-1)-2ab2-2, where a =-2 and b = 2.
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0
13 squared, (x-21y-1) (x-21y+1)-(x-21y-1).
[(X-2 is 1Y)- 1][(X+2 is 1Y)+ 1]-(X-2 is1y-0/) square.
= (x+ 1Y) square-1-(x- 1Y) square +2 (x- 1Y)- 1.
= (x+ 1Y) square -(x- 1Y) square +2 (x- 1y) -(X-2
=2XY+2X-Y-2
=3.9*2.4+ 1.4
= 10.76
14,2a-(3a-2b+2)+(3a-4b-1), where a=5 b=-3.
=2a-3a+2b-2+3a-4b- 1
=(2-3+3)a+(2-4)b+(-2- 1)
=2a-2b-3
= 10-(-6)-3
= 10+6-3
= 13
15,5-(1-x)-1-(x-1)-2x+(-5y), where x = 2 and y = 2x.
=4-2x-5y
=4-4-20
=-20
16, 2x-(x+3y)-(-x-y)-(x-y), where x = 3 and y =-3.
=2x-x+3y+x+y-x+y
=x+5y
=3- 15
=- 12
17, -ab+3ba-(-2ab), where a = 2 and b = 1.
=-ab+3ba+2ab
=2ab+2ab
=4ab
=4*2* 1
=8
18, -m-[-(2m-3n)]+[-(-3m)-4n], where m = 2 and n = 1.
=-m-(-2m+3n)+3m-4n
=-m-4m+2m-3n+3m
=-3n
=-3* 1
=-3
19,2 (2a+2ab)-2 (2ab-1)-2ab-2, where a=-2 b=2.
=4a+4ab-4ab+2-2ab-2
=4a-2ab
=4*(-2)-2*(-2)*2
=-8-(-8)
=8+8
=0
20,3ab-4ab+8ab-7ab+ab, where a =-2 and b = 3.
=-8ab+9ab
=ab
=-2*3
=-6
One-dimensional equation simplification evaluation exercise 2x+3x= 10
5x=5
x= 1
The first math problem in junior high school requires speed, and the linear equation is (80-20y)/3-6y=33.
80-20y- 18y=99
38y= - 19
y= - 1/2
Simplify and evaluate, and solve the unary linear equation with 50 methods;
3ab-4ab+8ab-7ab+ab=______。
7x-(5x-5y)-y=______。
23 a3 BC 2- 15 ab2c+8 ABC-24 a3 BC 2-8 ABC = _ _ _ _ _ _。
-7x 2+6x+ 13 x2-4x-5x 2 = _ _ _ _ _ _。
2y+(-2y+5)-(3y+2)=______。
. (2 x2-3xy+4 y2)+(x2+2xy-3 y2)= _ _ _ _ _ _。
2a-(3a-2 b+2)+(3a-4 b- 1)= _ _ _ _ _ _。
-6x2-7x2+ 15x2-2x2=______。
2x-(x+3y)-(-x-y)-(x-y)=______。
2x+2y-[3x-2(x-y)]=______。
5-( 1-x)- 1-(x- 1)= _ _ _ _ _ _。
Math problem of grade one in junior high school ~ One yuan meets an equation ~ A and B go from place A to place B at the same time. Party A rides a bike and Party B walks. The speed of Party A is three times that of Party B, exceeding 1 km. After arriving at B, Party A stayed for 45 minutes, then returned from B and met Party B on the way. At this time, it was just three hours before they set off. If the distance between the two places is 25.5 kilometers, what are the speeds of Party A and Party B respectively?
Let the speed of B be x, then the speed of A is 3x+ 1.
According to the question, the walking time of B is 3 hours, and the walking time of A is 3-0. 75=2。 25 hours
The following equation can be obtained:
3x+(3x+ 1)2.25=2x25.5
x=5
3x+ 1= 16
Then the speed of a is 16 km/h, and the speed of b is 5 km/h.
A, the distance between the two stations is 168km. The local train leaves from Station A at a speed of 36 kilometers per hour, and the express train leaves from bilibili at a speed of 48 kilometers per hour ... (1) The two trains leave at the same time, in opposite directions. How many hours did they meet?
I'll see you in x hours.
36x+48x= 168 x=2
The first question is difficult, and the second is simple. The problem of meeting is mainly to find their distance relationship. I hope it works for you!
The more the better 1 to solve the problem of a linear equation in junior high school mathematics. It is known that 4x2n-5+5=0 is a one-dimensional linear equation about x, then n = _ _ _ _ _ _
2. If x=- 1 is the solution of equation 2x-3a=7, then a = _ _ _ _ _
3. When x=______, the sum of algebraic expression x- 1 is opposite to each other.
4. It is known that the sum of x and 3 times of x is 6 less than 2 times of x, and the equation is _ _ _ _ _.
5. In the equation 4x+3y= 1, if y is expressed by the algebraic expression of x, then Y = _ _ _ _ _ _
6. When the purchase price of a commodity in 300 yuan is 60% off the list price, the profit rate is 5%, and the list price of the commodity is _ _ _ _ _ _ _.
7. Given that the sum of three consecutive even numbers is 60, these three numbers are _ _ _ _ _ _.
8. For a job, it takes 6 days for Party A to do it alone, 12 days for Party B to do it alone, and _ _ _ _ _ _ _ days for both parties to do it together.
Second, multiple choice questions. (3 points for each small question, * * * 30 points)
9. Equations 2m+x= 1 and 3x- 1=2x+ 1 have the same solution, then the value of m is ().
A.0 B. 1 C.-2 D
10. The solution of equation 3x =18 is ().
A. One solution is 6 B, and there are two solutions, both of which are 6.
C. No solution D. There are countless solutions
1 1. If the equation 2ax-3=5x+b has no solution, then a and b should satisfy ().
A.a，b≠3 B.a=，b=-3
C.a，b=-3 D.a=，b ≦- 3
12. The equation after converting the denominator of the equation into an integer is ().
13.800 meters on the runway, two people are practicing long-distance running. A runs 300 meters per minute, and B runs 260 meters per minute. They set out in the same place, at the same time and in the same direction, and met for the first time after t minutes, and t equals ().
A. 10 points B. 15 points C.20 points D.30 points.
14. A shopping mall found that the sales in the first quarter of this year increased by 10% in February and decreased by 10% in March, so the sales in March were higher than 1 month ().
A. increase10% B. decrease10% C. neither increase nor decrease D. decrease 1%.
15. in the trapezoid area formula S= (a+b)h, it is known that H = 6cm, A = 3cm and S = 24cm2, then B = () cm.
A. 1
16. It is known that there are 28 people in group A and 20 people in group B. Among the following deployment methods, the one that can make one group less than half of the other group is ().
A. transfer 12 people from group a to group b, and transfer 4 people from group b to group a.
C. transfer 12 people from group b to group a.
D transfer 12 people from group a to group b, or transfer 4 people from group b to group a.
17. The rules of football match are: win a game with 3 points, draw a game with 1 point, lose a game with 0 points, a team played 14 games and lost 5 games, and * * * got 19 points, so the team won () games.
a3 b . 4 c . 5d . 6
18. As shown in the figure, how many weights can be removed from the left plate in Figure A to keep the balance? ( )
A.3 B.4 C.5 D.6
Third, answer the question. (19, 20 questions 6 points, 2 1, 22 questions 7 points, 23 and 24 questions 10 points, ***46 points)
19. Solve the equation: -9.5.
20. Solve the equation: (x-1)-(3x+2) =-(x-1).
2 1. As shown in the figure, many information cards are neatly pasted on a display board. These cards are the same size, with three square spaces between them, which are marked with diagonal lines in the figure. Given that the short side length of the card is 10 cm, I want to match three pictures ... and expand them all.
The simplified evaluation of unary linear equation 80 has the answer 1. Suppose 4x2n-5+5=0 is a linear equation with one variable about x, then n = _ _ _ _ _
2. If x=- 1 is the solution of equation 2x-3a=7, then a = _ _ _ _ _
3. When x=______, the sum of algebraic expression x- 1 is opposite to each other.
4. It is known that the sum of x and 3 times of x is 6 less than 2 times of x, and the equation is _ _ _ _ _.
5. In the equation 4x+3y= 1, if y is expressed by the algebraic expression of x, then Y = _ _ _ _ _ _
The type problem of the linear equation in junior middle school mathematics is1.2 (x-2)-3 (4x-1) = 9 (1-x).
2. 1 1x+64-2x = 100-9x
3. 15-(8-5x)=7x+(4-3x)
4.3(x-7)-2[9-4(2-x)]=22
5.3/2[2/3( 1/4x- 1)-2]-x = 2
6.2(x-2)+2=x+ 1
7.0.4(x-0.2)+ 1.5=0.7x-0.38
8.30x- 10( 10-x)= 100
9.4(x+2)=5(x-2)
10. 120-4(x+5)=25
1 1. 15x+863-65x=54
12. 12.3(x-2)+ 1 = x-(2x- 1)
13. 1 1x+64-2x = 100-9x
14. 14.59+x-25.3 1=0
15.x-48.32+78.5 1=80
16.820- 16x=45.5×8
17.(x-6)×7=2x
18.3x+x= 18
19.0.8+3.2=7.2
20. 12.5-3x=6.5