\(\dfrac{x^4-xy^3}{2xy+y^2}:\dfrac{x^3+x^2y+xy^2}{2x+y}\)
\(=\dfrac{x\left(x^3-y^3\right)}{y\left(2x+y\right)}:\dfrac{x\left(x^2+xy+y^2\right)}{2x+y}\)
\(=\dfrac{x\left(x-y\right)\left(x^2+xy+y^2\right)}{y\left(2x+y\right)}:\dfrac{x\left(x^2+xy+y^2\right)}{2x+y}\)
\(=\dfrac{x\left(x-y\right)\left(x^2+xy+y^2\right)\left(2x+y\right)}{y\left(2x+y\right)x\left(x^2+xy+y^2\right)}\)
\(=\dfrac{x-y}{y}\)
ĐKXĐ: \(x,y\ne0;x\ne-\dfrac{1}{2}y\)
\(\dfrac{x^4-xy^3}{2xy+y^2}:\dfrac{x^3+x^2y+xy^2}{2x+y}\)
\(=\dfrac{x\left(x^3-y^3\right)}{y.\left(2x+y\right)}:\dfrac{x\left(x^2+xy+y^2\right)}{2x+y}\)
\(=\dfrac{x\left(x-y\right)\left(x^2+xy+y^2\right)}{y.\left(2x+y\right)}.\dfrac{2x+y}{x.\left(x^2+xy+y^2\right)}\)
\(=\dfrac{x-y}{y}\left(x;2x+y;x^2+xy+y^2\ne0\right)\)