Verified answer

Explications étape par étape:

Exercice 1:

1)A = 9n + 18

B = 2x + 6x²

C = 42 - 6y

D = 12 - 18x

2) E = 3(x+1)

F = a(b-4)

G = 3(3a - 4b)

H = 3( 3x² + x + 9)

3)

I = 9a + 8a - 28

I = 17a - 28

J = 8 + 6x + 12 - 4x

J = 2x + 20

Exercice 2:

83. × (49 -4) = 83 × 49 - 83 × 4

49 × 83 - 49 × 4 = 49 x (83-4)

83 × (49+4) = 83 × 49 + 83 × 4

49 × 83 + 49 × 4 = 49 × (83 +4)

Exercice3:

A = (108-8) × 26

A = 100 × 26

A = 2 600

B = 27 × (3+7)

B = 27 × 10

B = 270

C = 3 × (99-7)

C = 3× 92

C = 276