zoubia bonjour aidez moi a resoude mes exercice le plus rapidement possible* trove dans chaque cas x tel que 10x+12=42 ; ex2)   2*(x+6)-12=28  ; ex3 9(x+4)+x-16

10x + 12 = 42

10x + 12 - 12 = 42 -12

10x /10 = 30/10

x = 3

2*(x+6)-12=28

2x + 12 - 12 = 28

2x / 2 = 28 / 2

x = 14

9(x+4) + x - 16 = 20 

9x + 36 + x - 16 = 20

10x + 20 -20 = 20 - 20

10x = 0   

x = 0 car toute multiplication par 0 donne 0

2x + 5x + 8x = 30

15x /15 = 30 / 15

x = 2

5(x + 3) + 2x = 36

5x + 15 + 2x = 36

7x + 15 - 15 = 36 -15

7x / 7 = 21 / 7

x = 3

10 + 5(x - 2) = 40

10 + 5x - 10 = 40

5x / 5 = 40 / 5

x = 8