Sagot :
2x-3 = 5x-12
2x-5x = -12+3
-3x = -9
x = 3
5(x-2) = -x+7(x-1)
5x-10 = -x+7x-7
5x+x -7x = -7-10
-x = -17
x = 17
2x - 3 = 5x - 12
2x - 3 + 3 = 5x - 12 + 3
2x - 5x = 5x - 9 - 5x
- 3x /-3 = - 9 / - 3
x = 3
5(x - 2) = -x + 7(x - 1)
5x - 10 + 10 = -x + 7x - 7 + 10
5x - 6x = 6x + 3 - 6x
-x = 3
x = - 3