Sagot :
1) 3x- 5 = 2x 5
3x - 5 - 2x = 0
3x - 2x =5
x = 5
2) -3x + 6 = -3 3
-3x = -3 - 6
-3x = -9
x = 3
3) 2,5x- 6 = 0,5x +2 4
2,5x -0,5x = 6 + 2
2x = 8
x = 4
4) -x-2 = -2x + 3 5
-x +2x = 2 + 3
x = 5
5) 4x - 3 = 7x + 4 -7/3
-3 -4 = 7x - 4x
-7 = 3x
x = -7/3
6) -x + 1= 1 0 ou 2,5
-x = 1 - 1
-x = 0
x = 0
7) 2x-5=7 0 ou 6
2x = 7 + 5
2x = 12
x = 6