1) 2[3X( X-2 )]=3[2X(X-1)]+12
2) 2(X-2) - 3(X+1) - 5=3 - 5(X+1)
2006-11-01 12:54:01 · 4 個解答 · 發問者 becky94920 1 in 科學 ➔ 數學
1.
2[3X( X-2 )]=3[2X(X-1)]+12
2[3X^2 - 6X] = 3[2X^2 - 2X] + 12
6X^2 - 12X = 6X^2 - 6X + 12
-6X = 12
X = -2
2.
2(X-2) - 3(X+1) - 5=3 - 5(X+1)
2X - 4 - 3X - 3 - 5 = 3 - 5X - 5
-X -12 = -5X - 2
4X = 10
X = 5 / 2
2006-11-01 12:58:10 · answer #1 · answered by J 7 · 0⤊ 0⤋
1. 2[3X(X-2)]=3[2X(X-1)]+12
2(3X^2-6X)=3(2X^2-2X)+12
6X^2-12X=6X^2-6X+12
6X^2-6X^2=-6X+12X+12
0-12=6X
-12/6=X
X=-2
2. 2(X-2) - 3(X+1) - 5=3 - 5(X+1)
2X-4-3X-3-5=3-5X-5
-X-12=-2-5X
-X+5X=-2+12
4X=10
X=2.5
2006-11-01 14:44:46 · answer #2 · answered by 信 3 · 0⤊ 0⤋
2[3X( X-2 )]=3[2X(X-1)]+12
2[3X^2- 6X] = 3[2X^2- 2X]+ 12
6X^2- 12X = 6X^2- 6X+ 12
6X^2- 6X^2- 12X+6X = 12
-6X = 12
X = -2
2(X-2) - 3(X+1) - 5=3 - 5(X+1)
2X- 4 -3X- 3- 5 = 3- 5X- 5
2X- 3X+ 5X = 3- 5+ 4+ 3+ 5
4X = 10
X = 10/4
X = 5/2
2006-11-01 13:15:36 · answer #3 · answered by ? 2 · 0⤊ 0⤋
2 { 3x^2 -6x ] = 3[ 2x^2-2x] +12
6x^2 -12x = 6x ^2 -6x +12
-12 = 6x
x = -2
2x-2 -3x-3 -5 = 3- 5x-5
-x -7 = -2 - 5x
4x = 5
2006-11-01 12:59:55 · answer #4 · answered by ivan 2 · 0⤊ 0⤋