bonjour

30

a)

3/4 * x = 5

3/4 * 4/3 * x = 5 * 4/3

x = 20/3

b) 4x - 3 + 3 = 11 + 3

4x = 14

4x/4 = 14/4

x = 3,5

c) 7 - 7 - 8X = 56 - 7

-8x = 49

-8x/(-8) = 49/(-8)

x = -6,125

d) 6x - 4 + 4 = 3x + 14 + 4

6x - 3x = 3x - 3x + 18

3x=18

3x/3 = 18/3

x=6

et e)   9 - 9 - 2x = 11 - 9 + 4x

-2x - 4x = 2 + 4x - 4x

-6x = 2

x = -1/3

31

puisque k(a+b)=ka+kb

on aura

5x-15 - 3x + 7 = 5x-3x-15+7 = 2x-8

et b) 2x-8=9

2x=17

x=8,5