Bonsoir
A = (4x - 7)(x + 8)
A = 4x^2 + 32x - 7x - 56
A = 4x^2 + 25x - 56
C = (5x - 2)(-2x - 1)
C = -10x^2 - 5x + 4x + 2
C = -10x^2 - x + 2
B= (-2x + 3)(x + 2)
B = -2x^2 - 4x + 3x + 6
B = -2x^2 - x + 6
D= (3x – 5)2
D = 9x^2 - 30x + 25
Explications :
(a - b)^2 = a^2 - 2ab + b^2
(a - b)(c + d) = ac + ad - bc - bd
