Réponse :
Explications étape par étape
Exercice 2 :
a. 6 × a = 6a e. x × 9 = 9 × x = 9x
b. 8 × b = 8b f. y × 3 = 3 × y = 3y
c. 23 × d = 23d g. e × 5 = 5 × e = 5e
d. a × b = ab h. g × 12 = 12 × g = 12g
Exercice 3 :
a. 2 × 5 × d = 10 × d = 10d
b. 3 × e × 8 = 3 × 8 × e = 24 × e = 24e
c. g × 8 × 9 = 8 × 9 × g = 72 × g = 72g
d. 3 × (n + m) = 3 × n + 3 × m = 3n + 3m
e. (a + b) × 5 = 5 × (a + b) = 5 × a + 5 × b = 5a + 5b
f. b × (5 × e + 7) = b × (5e + 7) = b × 5e + b × 7 = 5e × b + 7 × b = 5eb +7b
g. 2.5 × d × (d × 9 + 7 × 3) = 2.5 × d × (9d + 21) = 2.5d × (9d + 21)
= 2.5d × 9d + 2.5d × 21 = 22.5d² + 52,5d
Exercice 4 :
a × 1 = a d × 0 = 0
g × 1 = g 0 × c = 0
1 × b = b m × 1 = m
Exercice 5 :
a. 2 × a + 5 × c = 2a + 5c
b. a × d + 5 × 8 = ad + 40
c. 38 × (3 + 2 × c) = 38 × (3 + 2c) = 38 × 3 + 38 × 2c = 114 + 76c
d. 3 × z - 0 × b = 3z - 0 = 3z
e. 3 × 7 - d × b = 21 - db
f. a × (3 × 9 + b × n) = a × (27 + bn) = a × 27 + a × bn = 27a + bna
g. 0 × u + 1 × m = 0 + m = m
h. a × 6 × n + 3 × p = 6a × n + 3 × p = 6an + 3p
i. 9 × m × 5 + k × j × 8 = 9m × 5 + kj × 8 = 45m + 8kj
Exercice 6 :
a. 6 × 6 = 6 au carré (6²)
b. n × n = n au carré (n²)
c. b × b = b au carré (b²)
d. 23 × 23 = 23 au carré (23²)
e. 4 × 4 × 4 = 4 au cube (4³)
f. r × r × r = r au cube (r³)
g. 2 × 2 × p = 2 au carré (2²) × p
h. r × r × t × t × t = r au carré (r²) × t au cube (t³)
i. 3 × 3 × n × n = 3 au carré (3²) × n au carré (n²)
j. 1 × 1 × 1 × y × y = 1 au cube (1³) × y au carré (y²)
k. 2 × 2 × π × π = 2 au carré (2²) × π au carré (π²)
l. d × d × d × 6 × 6 = d au cube (d³) × 6 au carré (6²)