Question

Phân tích đa thức thành nhân tử :x³- x² - 4

Answer 1

x³-x²-4=x³-2x²+x²-4=x²(x-2)+(x-2)(x+2)=(x-2)(x²+x+2)

Answer 2

\(x^3-x^2-4\)

\(=x^3+x^2-2x^2-4\)

\(=\left(x^3-2x^2\right)+\left(x^2-4\right)\)

\(=x^2\left(x-2\right)+\left(x+2\right)\left(x-2\right)\)

\(=\left(x-2\right)\left(x^2+x+2\right)\)