Question

(xy-1)^2-(xy-1)(xy+2) Phân tích đa thức thành nhân tử

Answer 1

\(=\left(xy-1\right)\left(xy-1-xy-2\right)=-3\left(xy-1\right)\)

Answer 2

\(\left(xy-1\right)^2-\left(xy-1\right)\left(xy+2\right)=\left(xy-1\right)\left[\left(xy-1\right)-\left(xy+2\right)\right]=\left(xy+1\right)\left(xy-1-xy-2\right)=\left(xy-1\right)\left(-3\right)\)