Răspuns:
ex.11
4 - 3 • x = 5x
4 -3x = 5x
4 = 5x-3x
4 = 8x
x= 4 supra 8 = 1 supra 2
ex.29
4 - x = 7
-x = 7 - 4
-x = 3
ex.30
27 - x = +3,5
27 - 3,5 = x
x = 23,5
ex.16
2 • x - 7 = 11
2x- 7 = 11
2x = 11 + 7
2x= 18
x= 18 supra 2
x = 9
ex.17
- 2x + 7 = 11
-2x = 11 - 7
-2x = 4
x= - 2 supra 4 = - 1 supra 2