Bonjour

a) 2x + 3 = - 7

2x = - 7 - 3

2x = - 10

x = - 10/2

x = - 5

b) 4 - 12x = - 8 - 14x

- 12x + 14x = - 8 - 4

2x = - 12

x = - 12/2

x = - 6

c) 5 (2x + 3) = 15 + x

10x + 15 = 15 + x

10x - x = 15 - 14

9x = 0

x = 0

d) 2/3x = - 4/5

10x = - 8

x = - 8/10

x = - 2/4

e) 7x + 2/5 = 5x - 1/10

7x - 5x = - 1/10 - 4/10

2x = - 5/10

2x = - 1/2

4x = - 1

x = - 1/4.