8) Ta có: \(x^2y+xy^2-4x-4y\)
\(=xy\left(x+y\right)-4\left(x+y\right)\)
\(=\left(x+y\right)\left(xy-4\right)\)
12) Ta có: \(a^2+2ab+b^2-ac-bc\)
\(=\left(a+b\right)^2-c\left(a+b\right)\)
\(=\left(a+b\right)\left(a+b-c\right)\)
10: Sửa đề: \(a^3-a^2x-ay+xy\)
Ta có: \(a^3-a^2x-ay+xy\)
\(=a^2\left(a-x\right)-y\left(a-x\right)\)
\(=\left(a-x\right)\left(a^2-y\right)\)