Question

Phân tích đa thức thành nhân tử :

1) x³ - x²y - xy + y²

2) x² - 2xy + x - 2y

3) x² + 4xy +3y²

Answer 1

1 ) \(x^3-x^2y-xy+y^2\)

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

\(=x^2.\left(x-y\right)-y.\left(x-y\right)\)

\(=\left(x-y\right).\left(x^2-y\right)\)

2 ) \(x^2-2xy+x-2y\)

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

\(=x.\left(x+1\right)-2y.\left(x+1\right)\)

\(=\left(x+1\right).\left(x-2y\right)\)

3 ) \(x^2+4xy+3y^2\)

\(=x^2+3xy+xy+3y^2\)

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

\(=x.\left(x+3y\right)+y.\left(x+3y\right)\)

\(=\left(x+3y\right).\left(x+y\right)\)

Answer 2

Sgk trang may vay