grupezi termeni pt a da factor comun
a)x^2(x-1)-9(x-1)=(x-1)(x^2-9)=(x-1)(x-3)(x+3)
b)x^2(x-1)-4(x-1)=(x-1)(x^2-4)=(x-1)(x-2)(x+2)
c)x^2(x+2)-(x+2)=(x+2)(x^2-1)=(x+2)(x-1)(x+1)
j)x^2(x-4)-4(x-4)=(x-4)(x-2)(x+2)
k)x^2(x+3)-4(x+3)=(x+3)(x^2-4)=(x+3)(x-2)(x+2)
l)x^2(x+3)-9(x+3)=(x+3)(x^2-9)=
(x+3)(x-3(x+3)=(x+3)^2(x-3)
