Bonjour,
Exercice 15 :
A = 3 × (x + 2) = 3 × x + 3 × 2 = 3x + 6
B = (x + 6) × 7 = 7 × x + 7 × 6 = 7x + 42
C = 4(x + 1) = 4 × x + 4 × 1 = 4x + 4
D = 8(2 + x) = 8 × 2 + 8 × x = 8x + 16
Exercice 16 :
E = 9 × (x - 3) = 9 × x - 9 × 3 = 9x - 27
F = 4 × (5 - x) = 4 × 5 - 4 × x = -4x + 20
G = 7(x - 8) = 7 × x - 7 × 8 = 7x - 56
H = 6(9 - x) = 6 × 9 - 6 × x = -6x + 54
