Question

Phân tích đa thức sau thành nhân tử:

x^3 -2x^2-x+2

Answer 1

x³-2x²-x+2

=x³-x²-x²+x-2x+2

=x²(x-1) -x(x-1) -2(x-1)

=(x²-x-2)(x-1)=(x²-2x+x-2)(x-1)

=(x-2)(x+1)(x-1)

Answer 2

(x^3-2x^2-x+2\ =x^3-x^2-x^2+x-2x+2\ =x^2left(x-1 ight)-xleft(x+1 ight)-2left(x+1 ight)\ =left(x+1 ight)left(x^2-x-2 ight)\ =left(x+1 ight)left(x^2+x-2x-2 ight)\ =left(x+1 ight)^2left(x-2 ight))