Réponse :

bonjour

Explications étape par étape :

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

2(12 - 6x) = 3

24 - 12x = 3

- 12x = 3 - 24

- 12x = - 21

12x = 21

x = 21/12

x = 7/4

f)

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

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

3x/3 = -2 /5

x = - 2/5

bonne journée