Bonsoir j'aurais besoins d'aide pour le e !Merci niveau 4 eme

d)
3 (2t + 5) = 4 (5t + 7)
6t + 15 = 20t + 28
6t - 20t = 28 - 15
- 14t = 13
t = - 13/14

e)
2 (3x + 4) - 5 (1 - 2x) = 7 (2x - 3) + 12
6x + 8 - 5 + 10x = 14x - 21 + 12
6x + 10x - 14x = - 21 + 12 - 8 + 5
2x = - 12
x = - 12/2
x = - 6

f)
(2x + 1) - x = x - 5
2x + 1 - x = x - 5
2x - x - x = - 5 - 1
2x - 2x = - 6
0x = - 6
x = 0