2x-3(x+5)=5x-21
7(x-1)-4(x+3)=2
15-(x-6)=6-(3x+5)
7(x-3)=3(-4+3x)+1 要step牙thx))*
2006-10-25 14:57:00 · 4 個解答 · 發問者 Anonymous in 科學 ➔ 數學
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。
2006-10-25 15:24:34 · answer #1 · answered by Michael Tse 1 · 0⤊ 0⤋
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
2006-10-25 15:02:58 · answer #2 · answered by Amby 6 · 0⤊ 0⤋
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
2006-10-25 15:02:27 · answer #3 · answered by J 7 · 0⤊ 0⤋
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
2006-10-25 15:02:05 · answer #4 · answered by 英王的教室 7 · 0⤊ 0⤋