SVP,AIDEZ MOI A FAIRE CA. MERCI BEAUCOUP

Salut,

Exercice 7 :

B = 5x² + 3x² = (5+3)x² = 8x²
C = 5u - u = (5-1)u = 4u
D = a² - 5a² + 2a² = (1-5+2)a² = -2a²
E = 3/5 x + 1/5x = (3/5 + 1/5)x = 4/5x
F = (1/3y² + 5/6y² = (1/3 + 5/6)y² = (2/6 + 5/6)y² = 7/6y²

Exercice 8:

à entourer : a + 1 + a + a + 1 + 1 + 1 + a + a +a
et 2a + 2 + 2a + 2 + 2a

b.

2a + 2 + 2a + 2 + 2a = (2+2+2)a + 2 + 2 = 6a + 4

Exercice 5 :

7x + 3 = 7x + 3
7x + 3x = (7+3)x = 10x
7x - 3x = (7-3)x = 4x
7x * 3 = (7*3)x = 21x
5x + 5x = (5+5)x = 10x
7x * 3x = (7*3) * (x*x) = 21x²

Bonne soirée !