a) Sửa đề: \(3x\left(2xy-x^2\right)+5\left(x-2y\right)^2\)
Ta có: \(3x\left(2xy-x^2\right)+5\left(x-2y\right)^2\)
\(=3x^2\left(2y-x\right)+5\left(2y-x\right)^2\)
\(=\left(2y-x\right)\left[3x^2+5\left(2y-x\right)\right]\)
\(=\left(2y-x\right)\left(3x^2+10y-5x\right)\)
c)Ta có: \(x\left(y-2015\right)+2016\left(2015-y\right)\)
\(=x\left(y-2015\right)-2016\left(y-2015\right)\)
\(=\left(y-2015\right)\left(x-2016\right)\)