besoin d'aide.. le 9 & le 29

Exercice 8 :

a) A = B
2x + 3 = 5 - 4x
2x + 4x = 5 - 3
6x = 2
x = 2/6
x = 1/3

b) B = C
5 - 4x = -1/3 + x
5 + 1/3 = x + 4x
15/3 + 1/3 = 5x
16/3 = 5x
x = 16/3 * 1/5
x = 16/15

c) A = C
2x + 3 = -1/3 + x
2x - x = -1/3 -3
x = -1/3 -9/3
x = -10/3.


Exercice 29 :

a) A = 2*(3-4x)
= 2*3 - 2*4x
= 6 - 8x

b) B = 10 - 3*x + 2
= 12 - 3x

Après, je ne vois pas très bien le reste de ton exercice.
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