a)x²(x-1)-9(x-1)=
(x-1)(x²-9)=
(x-1)(x-3)(x+3)
b)x²(x-1)-4(x-1)=
(x-1)(x²-4)=
(x-1)(x-2)(x+2)
c)x²(x+2)-(x+2)=
(x+2)(x²-1)=
(x+2)(x-1)(x+1)
d)x²(x-4)-4(x-4)=
(x-4)(x²-4)=
(x-4)(x-2)(x+2)
e)x²(x+3)-4(x+3)=
(x+3)(x²-4)=
(x+3)(x-2)(x+2)
f)x²(x+3)-9(x+3)=
(x+3)(x²-9)=
(x+3)²(x-3)