J'ai besoin de vous, je suis coincé pour des équations : a: 7x+11=5x-12 b: 7x-7=4x-7 c: 7(x-7)-(4x+11)=4x-12

7x + 11 = 5x - 12
7x - 5x = - 12 - 11
2x = - 23
x = - 23/2

7x - 7 = 4x - 12
7x - 4x = 7 - 12
3x = - 5
x = - 5/3

7(x - 7) - (4x + 11) = 4x - 12
7x - 49 - 4x - 11 = 4x - 12
3x - 60 = 4x - 12
3x - 4x = - 12 + 60
- x = 48
x = - 48