好梗要=)*thx

1 .2x-3(x+5)=5x-21
2x-3x-15=5x-21
-6x=-6
x=1

2. 7(x-1)-4(x+3)=2
7x-7-4x-12=2
3x=21
x=7

3. 15-(x-6)=6-(3x+5)
15-x+6=6-3x-5
2x=-20
x=-10

4. 7(x-3)=3(-4+3x)+1
7x-21=-12+9x+1
-2x=10
x=-5

希望可以幫到你。

2x-3(x+5)=5x-21
2x-3x-15=5x-21
6x=6
x=1

7(x-1)-4(x+3)=2
7x-7-4x-12=2
3x-19=2
3x=21
x=7

15-(x-6)=6-(3x+5)
15-x+6=6-3x-5
9-x=1-3x
2x=-8
x=-4

7(x-3)=3(-4+3x)+1
7x-21=-12+9x+1
2x=-10
x=-5

2006-10-25 19:04:28 補充：
15-(x-6)=6-(3x+5)15-x+6=6-3x-521-x=1-3x2x=-20x=-10

2x - 3(x + 5) = 5x - 21
2x - 3x - 15 = 5x - 21
-6x = -6
x = 1

7(x - 1) - 4(x + 3) = 2
7x- 7 - 4x - 12 = 2
3x -19 =2
3x = 21
x = 7

15 - (x - 6) = 6 - (3x + 5)
15 - x + 6 = 6 - 3x - 5
21 -x = 1 - 3x
-4x = 20
x = -5

7(x - 3) = 3(-4 + 3x ) + 1
7x - 21 = -12 + 9x + 1
-2x = 10
x = -5

1.
2x-3(x+5)=5x-21
2x-3x-15=5x-21
-6x=-6
x=1

2.
7(x-1)-4(x+3)=2
7x-7-4x-12=2
3x=21
x=7

3.
15-(x-6)=6-(3x+5)
15-x+6=6-3x-5
2x=-20
x=-10

4.
7(x-3)=3(-4+3x)+1
7x-21=-12+9x+1
-2x=10
x=-5