bonjour,
il faut trouver le facteur commun
A = (x+2)(3+5)
= 8(x+2)
B = (x-3)(2x+1+3x-5)
= (x-3)(5x-4)
C = il manque le signe entre (x+4) et (x+5)(2x+3)
D = x²-9 =a²-b² = (x-3)(x+3)
E = 5a(5a-4)
F = 16c²+56c+49 =a²+2ab+b² =(a+b)² =(4c+7)²
G = (x+1)²-2(x+1)(-3x+5)
=(x+1)[(x+1)-2(-3x+5)]
= (x+1)(x+1+6x-10)
= (x+1)(7x-3)
K = -(x-1)(3x+6)-(2x-5)(x-1)
= (x-1)[-(3x+6)-(2x-5)]
= (x-1)(-3x-6-2x+5)
= (x-1)(-5x-1)
