bjr
N = 2x² + 3x = x * 2x + x * 3 = x (2x+3)
0 = (3x + 2)(4x + 2) + (3x + 2)(2x - 8)
0 = (3x+2) [(4x+2) + (2x-8)]
0 = (3x+2) (4x+2+2x-8)
0 = (3x+2) (6x-6)
0 = 6 (3x+2) (x-1)
P = 25x² - 9 = (5x)² - 3²
= (5x+3) (5x-3) puisque a² - b² = (a+b) (a-b)
Q = (7x + 4)(-4x + 2) - (7x + 4)(-3x + 7)
voir le 0
R = (3x + 2)2-(3x + 2)(7x+ 5) = (3x+2) (3x+2) - (3x+2) (7x+5) => voir le 0
S = (-3x - 2)² - (7x + 3)² => voir le P
