Réponse :

Explications étape par étape :

exo 10

x + 3 = - 4

x = - 4 - 3

x = -7

4 x = 10

x = 10/4

5 x + 3 = 38

5 x = 38 - 3

5 x = 35

x = 35/5

X = 7

exo 11

3 x - 8 = 10

3 x = 10 + 8

3 x = 18

x = 18/3

x = 6

- 4 x + 6 = - 7

- 4 x = - 7 - 6

- 4 x = - 13

x = 13/4

exo 12

8 x + 3 =  3 x + 9

8 x - 3 x = 9 - 3

5 x = 6

x = 6/5

2 x - 3 = - 3 x + 2

2x + 3 x = 2 + 3

5 x = 5

x = 5/5

x=  1

exo 13

4 x + 17 = 3 x + 9

4 x - 3 x = 9 - 17

x = - 8

2 x + 3 = - 3 x + 2

2 x + 3 x = 2 - 3

5 x = - 1

x = - 1/5