a) déjà factorisé
b)
f(x) = x²-4(x-5)²
f(x) = x² - [ 2(x-5) ]²
f(x) = [x - (2x-10)] ( x +2x-10)
f(x)=(x-2x+10)(x+2x-10)
f(x) = (-x+10)(3x-10)
c)
f(x)=2(x-3)(x+7)-(2x+1)(x+7)
f(x)=(2x-6)(x+7)-(2x+1)(x+7)
f(x)=(x+7)(2x-6-2x-1)
f(x)=-7(x+7)
d)déjà factorisé
e)
f(x)=(x-2)(x+1)-(x²-4)
f(x)=(x-2)(x+1)-(x²-2²)
f(x)=(x-2)(x+1)-(x-2)(x+2)
f(x)=(x-2)(x+1-(x+2)
f(x)=(x-2)(x+1-x-2)
f(x)=(x-2)(-1)
f(x)=-x+2
f)
f(x)=x²-12x+36
(a-b)²=a²-2ab+b²
f(x)=(x-6)²
g)
f(x)=x(3x-5)-(3x-5)
f(x)=(3x-5)(x-1)
h)
f(x)=x²-1-3x(x+1)
f(x)=(x-1)(x+1)-3x(x+1)
f(x)=(x+1)(x-1-3x)
f(x)=(x+1)(-2x-1)
