bonsoir
a) 3 x - x = 2 - 7
2 x = - 5
x = - 5/2
b) 2 y - 3 y = - 1 - 2
- y = - 3
y = 3
c) - 5 a - 2 a = - 1 - 4
- 7 a = - 5
a = 5/7
d ) t + 3 t = - 10 + 4
4 t = - 6
t = - 6/4 = - 3/2
e) 2 x - 5 = 3 x + 5
2 x - 3 x = 5 + 5
- x = 10
x = - 10
f) - 12 - 4 x = 2 x - 6
- 4 x - 2 x = - 6 + 12
- 6 x = 6
x = - 1