Bonjour pouvez vous m’aidez pour ces exercices 4 et 5 svp merci

bjr

ex 5

7 + a = 17 + 3a

a - 3a = 17 - 7

-2a = 10

a = 10/(-2)

a = -5

2 (b+4) = -2

2*b + 2*4 = -2

2b + 8 = -2

2b = -10

b = -10/2

b = -5

2(4x - 5) = 7x - 5

2*4x + 2*(-5) = 7x - 5

8x - 10 = 7x - 5

8x - 7x = -5 + 10

x = 5