Question

PT đa thức thành nhân tử: 

a) x^3-2x^2y-4x+8y

b) a^2x^2-a^2y^2-b^2x^2+b^2y^2

Answer 1

a: Ta có: \(x^3-2x^2y-4x+8y\)

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

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

b: Ta có: \(a^2x^2-a^2y^2-b^2x^2+b^2y^2\)

\(=a^2\left(x-y\right)\left(x+y\right)-b^2\left(x-y\right)\left(x+y\right)\)

\(=\left(x-y\right)\left(x+y\right)\left(a-b\right)\left(a+b\right)\)