Question

解一元一次方程的练习题附答案

Answer 1

一元一次方程 有答案
1、x/4=-x/2+3
x/4+x/2=3
3x/4=3
x=4
2、1/2（x*x-y）+1/3（x-y*y）+1/6（x*x+y*y）
=1/2x^2-1/2y+1/3x-1/3y^2+1/6x^2+1/6y^2
=2/3x^2-1/2y+1/3x-1/6y^2

3、x/4=-x/2+3 4、
x/4+x/2=34
3x/4=34
x=34
4、（x+0.5）+x=17
2x=17-0.5
x=8.25
5、x+14/7=x+20/4
4(x+14)=7(x+20)
4x+56=7x+140
3x=-84
x=-28
6、x+15/5=1/2— x—7/3
6(x+15)=15-10(x-7)
6x+90=15-10x+70
16x=-5
x=-5/16
7、-3x=15
x=15/(-3)
x=-5
8、-n/3-2=10
-n/3=12
n=-36
9、3x+3=2x+7
3x-2x=7-3
x=4
10、5/12x-x/4=1/3
5x-3x=4
2x=4
x=2

11、2/3—8x=3-x/2
4-48x=3(3-x)
4-48x=9-3x
-45x=5
x=-1/9
12、0.5x-0.7=6.5-1.3x
0.5x+1.3x=6.5+0.7
1.8x=7.2
x=4
13、3x-6/6=2x/5 -3
5(3x-6)=12x-90
15x-30=12x-90
3x=-60
x=-20

没有答案
1. 2(x-2)-3(4x-1)=9(1-x)
2. 11x+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
11. 15x+863-65x=54
12. 12.3(x-2)+1=x-(2x-1)
13. 11x+64-2x=100-9x
14. 14.59+x-25.31=0
15. x-48.32+78.51=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
21. 1.2(x-0.64)=0.54
22. x+12.5=3.5x
23. 8x-22.8=1.2
24. 1\ 50x+10=60
25. 2\ 60x-30=20
26. 3\ 3^20x+50=110
27. 4\ 2x=5x-3
28. 5\ 90=10+x
29. 6\ 90+20x=30
30. 7\ 691+3x=700

多项式计算
1. (14x^2+12x^3y+16x^4y^3)/(-4x^2)
=7/2-3xy-4x^2y^3

2.(16×10^17)/(0.2×10^7)
=16/0.2
=80

3. -4/3a^2b^2(3/2a^2+9/4ab-27/8b^2)
=-2a^4b^2-3a^3b^3+9/2a^2b^4

4. (x-2)(x-3)+2(x+6)(x-5)-3(x^2-7x+3)
=x^2-5x+6+2x^2+2x-60-3x^2+21x-9
=18x-63
(1)(x+2y)(5a+3b)； (2)(2x-3)(x+4)；

(3)(x+y)2； (4)(x+y)(x2-xy+y2)

解：(1)(x+2y)(5a+3b)

＝x·5a+x·3b+2y·5a+2y·3b

＝5ax+3bx+10ay+6by；

(2)(2x-3)(x+4)

=2x2+8x-3x-12

=2x2+5x-12

(3)(x+y)2

=(x+y)(x+y)

=x2+xy+xy+y2

=x2+2xy+y2；

(4)(x+y)(x2-xy+y2)

=x3-x2y+xy2+x2y-xy2+y3

=x3+y3

Answer 2

2(x-2)-3(4x-1)=9(1-x)

2X-4-12X+3=9-9X
-10X-7=9-9X
-10X+9X=9+7
-X=16
X=-16

Answer 3

x+5=15
x=15-5
x=10

Answer 4

任务 0.........................