Question

phân  tích thành nhân tử a) x^3 - 8y^3 -  2xy(x-2y)

b)2x^2-3x-2

Answer 1

\(x^3-8y^3-2xy\left(x-2y\right)=\left(x-2y\right)\left(x^2+2xy+4y^2\right)-2xy\left(x-2y\right)\)

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

\(2x^2-3x-2=2x^2-4x+x-2=2x\left(x-2\right)+x-2=\left(2x+1\right)\left(x-2\right)\)

Answer 2

a)(x³-2x²y)+(4xy²-8y³)=x²(x-2y)+4y²(x-2y)=(x-2y)(x²+4y²)

b)(2x²-4x)+(x-2)=2x(x-2)+(x-2)=(x-2)(2x+1)