équations: a) 3x + 2 = 0 b) 4 - 5x = 0 c) 7x + 8 = 0 d) 9x - 4 = 0 e) 5x + 4 = 0

a) 3x + 2 = 0
3x + 2 - 2 = 0 - 2
3x = - 2
x = - 2 / 3

b) 4 - 5x = 0 
-5 x + 4 - 4 = 0 - 4
-5x = -4
- 4 / - 5
x = 0.8

c) 7x + 8 = 0
7x + 8 - 8 = 0 - 8
7x = -8
x = - 8 / 7

d) 9x - 4 = 0
9x - 4 + 4 = 0 + 4
9x = 4
x = 4 / 9

e) 5x + 4 = 0
5x + 4 - 4 = 0 - 4
5x = - 4
x = - 0.8