1) \(3x^2-3xy-5x+5y\)
\(=\left(3x^2-3xy\right)-\left(5x-5y\right)\)
\(=3x\left(x-y\right)-5\left(x-y\right)\)
\(=\left(3x-5\right)\left(x-y\right)\)
3) \(3x^2+6xy+3y^2-3z^2\)
\(=\left(3x^2+6xy+3y^2\right)-3z^2\)
\(=3\left(x^2+2xy+y^2\right)-3z^2\)
\(=3\left(x+y\right)^2-3z^2\)
\(=3\left[\left(x+y\right)^2-z^2\right]\)
\(=3\left(x+y+z\right)\left(x+y-z\right)\)
5) \(xy-5y+2x-10\)
\(=\left(xy-5y\right)+\left(2x-10\right)\)
\(=y\left(x-5\right)+2\left(x-5\right)\)
\(=\left(y+2\right)\left(x-5\right)\)
7) \(5x^3+10x^2y+5xy^2\)
\(=5x\left(x^2+2xy+y^2\right)\)
\(=5x\left(x+y\right)^2\)
9) \(2x^3y-2xy^3-4xy^2-2xy\)
\(=2xy\left(x^2-y^2-2y-1\right)\)
\(=2xy\left[x^2-\left(y^2+2y+1\right)\right]\)
\(=2xy\left[x^2-\left(y+1\right)^2\right]\)
\(=2xy\left(x-y-1\right)\left(x+y+1\right)\)
1: \(3x^2-3xy-5x+5y=3x\left(x-y\right)-5\left(x-y\right)=\left(x-y\right)\left(3x-5\right)\)
