Bonjour
Exercice 1 :
Développer les expressions
A = x (x + 2) = x² + 2x
B = 5x (x+3) = 5x² + 15x
C = 2x (3x – 5) = 6x² - 10x
D= - 3x (1 - 4x) = - 3x + 12x²
E = x (-x+3) = - x² + 3x
F = 2x (4x - 1) = 8x² - 2x
G=-3y (6 – 2y) = - 18y + 6y²
Exercice 2 :
Développer et réduire
A = (x+3) x - 2x (x+5)
A = x² + 3x - 2x² - 10x
A = - x² - 7x
B= -x (7x+8) -5 (3x+1)
B = - 7x² - 8x - 15x - 5
B = - 7x² - 23x - 5
C = 3x (7x-1) -2x (3x-2)
C = 21x² - 3x - 6x² + 4x
C = 15x² + x.