超難數學題～

1. 2(x-3)=3x 2x-6=3x x=-6
2.7(y+2)=5y-4 7y+14=5y-4 2y=-18 y=-9
3.m-3=8(2-m) m-3=16-8m 9m=19 m=19/9
4.p-2(p-4)=-3 p-2p+4=-3 -p=-7 p=7
5.4(y-1)=3(2-y) 4y-4=6=3y y=10
6.9(y+2)=6(y-3) 9y+18=6y-18 3y=-36 y=-12
7.3(7-2m)=5(2-m) 21-6m=10-5m m=11
8.3p=2(p-5)-(p+1) 3p=2p-10-p-1 2p=-11 p=-5.5
9.4+m/7=1 28+m=7 m=-21
10.p/4+p=5 p+4p=20 p=4
11.x/2+x/5=2 5x+2x=20 x=20/7
12.y/4-2y/3=1 3y-8y=12 y=-12/5
13.7-k/4=k/10 280-10k=4k 14k=280 k=20
14.3x/2=x-1/7 21x=14x-2 7x=-2 x=-2/7
15.y-1/3=2y+1/5 15y-5=30y+3 15y=-8 y=-8/15
16.3-m/6=1-2m/3 18-m=6-4m 3m=-12 m=-4
17.k/2-2k+4/3=1 3k-12k+8=12 -9k=4 k=-4/9
18.6b2-5-4b2 = 2b2-5
19.5d3-2+4d3+a =d3+a-2
20.y2-y3+y2+2y3 =2y2+y3
21.5x-2y-6y-4x = x-8y
22.2xy3+3x2y-xy2+x2y =xy(2y2+3x-2+x)

2010-10-03 18:38:12 補充：
更正
4.p-2(p-4)=-3 p-2p+8=-3 -p=-11 p=11
5.4(y-1)=3(2-y) 4y-4=6-3y 7y=10 y=10/7
17.k/2-2k+4/3=1 3k-12k+8=6 -9k=-2 k=2/9
樓下個個跟住錯...

1.2(x-3)=3x
2x-6=3x
-6=x
x= -6

2.7(y+2)=5y-4
7y+14=5y-4
7y-5y= -4-14
2y= -18
y= -9

3. m-3=8(2-m)
m-3=16-8m
m+8m=16+3
9m=19
m=19/9 or 2.11111111111111

4.p-2(p-4)=-3
p-2p+4=-3
p-2p=-3-4
-p=-7
p=7

5.4(y-1)=3(2-y)
4y-4=6-3y
4y+3y=6+4
y=10

6.9(y+2)=6(y-3)
9y+18=6y-18
9y-3y= -18-18
6y= -36
y= -6

7.3(7-2m)=5(2-m)
21-6m=10-5m
-6m-5m=10-21
-11m= -11
m=1

8.3p=2(p-5)-(p+1)
3p=2p-10-p-1
3p=p-11
3p-p= -11
2p=-11
p= -5.5 or -11/5

9.4+m/7=1
m/7=1-4
m/7= -3
m/7*7= -3*7
m= -21

10.p/4+p=5
4(p/4+p)=4(5)
p+4p=20
5p=20
p=4

11. x/2+x/5=2
10(x/2+x/5)=10(2)
5x+2x=20
7x=20
x=20/7

2010-10-03 18:30:46 補充：
12. y/4-2y/3=1
12(y/4-2y/3)=12(1)
3y-8y=12
-5y=12
y=-12/5

13. 7-k/4=k/10
40(7-k/4)=40(k/10)
210-10k=4k
-10k-4k=-210
-14k=-210
k=15

2010-10-03 18:31:10 補充：
14. 3x/2=x-1/7
14(3x/2)=14(x-1/7)
7x=14x-2
7x-14x= -2
-7x= -2
x=2/7

15. y-1/3=2y+1/5
15(y-1/3)=15(2y+1/5)
15y-5=30y+3
15y-30y=3+5
15y=8
y=8/15

2010-10-03 18:31:27 補充：
16. 3-m/6=1-2m/3
18(3-m/6)=18(1-2m/3)
54-3m=18-12m
-3m+12m=18-54
9m= -36
m= -4

2010-10-03 20:44:59 補充：
17.k/2-2k+4/3=1
6(k/2-2k+4/3)=6(1)
3k-12k+8=6
-9k=6-8
-9k= -2
k=2/9

18. 6b2-5-4b2
=2b2-5

2010-10-03 20:50:07 補充：
19. 5d3-2+4d3+a
=d3-2+a

20. y2-y3+y2+2y3
=2y2+3y3

21. 5x-2y-6y-4x
= -5y-2y

22. 2xy3+3x2y-xy2+x2y
=xy(2y2+3x-2+x)

2010-10-03 20:52:02 補充：
sorry 第五條錯咗
5.4(y-1)=3(2-y)
4y-4=6-3y
4y+3y=6+4
( y=10 ) <== 7y=10
y=10/7