bonsoir merci de m'aider pour mes maths.​

Bonsoir

a. 5x - 7 = 8

5x = 8 + 7

5x = 15

x = 15/5

x = 3

b. - 2 = 18 + 10y

10y = - 2 - 18

10y = - 20

y = - 20/10

y = - 2

c. 7 + 9y = - 29

9y = - 29 - 7

9y = - 36

y = - 36/9

y = - 4.

d. 3 (x - 1) = 3

3x - 3 = 3

3x = 3 + 3

3x = 6

x = 6/3

x = 2

e. 12 - 6x = 3/2

- 6x = 3/2 - 12

- 6x = 3/2 - 24/2

- 12x/2 = 3/2 - 24/2

- 12x = 3 - 24

- 12x = - 21

x = 21/12

f. 5/3x + 1/5 = 2/3x - 1/5

5/3x - 2/3x = - 1/5 - 1/5

3/3x = - 2/5

x = - 2/5.