Réponse:
Bonjour,
3x - 4x + 5x
= -x + 5x
= 4x
7a + 3a - 2a
= 10a - 2a
= 8a
13x - 2 + 4x - 1
= 13x + 4x - 2 - 1
= 17 x -3
2x(2) + 4y - 6x - x(2) - y
= 2x*2 + 4y - 6x - x*2 - y
=4x + 4y - 6x - 2x - y
= 4x - 6x - 2x + 4y - y
= - 4x + 3y
(2x + 3) - (x-2)
= 2x + 3 - x + 2
= 2x - x + 3 + 2
= x + 5
