Réponse:
a) 4×(2x +3)
= 4×2x + 4×3
= 8x + 12
b) 5+(2x +3)
= 5 +2x +3
= 2x +5+3
= 2x +8
c) (5 +2x)
= 5 +2x. il n'y a pas une multiplication pour effectuer la distributivité .
d) 4×(5x -2)
= 4×5x - 4×2
= 20x -8
e) 4×(5x × 2)
= 4×10x
= 40x
f) 4×(3×x +2)
= 4×(3x +2)
= 4×3x + 4×2
= 12x +8
Exercice 58 :
a) 103 × 25
= 2575
b) 21 × 14
= 294
c) 98 × 15
= 1470