common factor 8y^3-20y^2?
8y^3-20y^2
\(\;\;\;\;8y^3\qquad-\qquad20y^2\\ =4y^2*2y\;\;\;-\;\;\;4y^2*5\\ The\;highest\;commom\;factor\;is\;4y^2\\ Factorised\;it\;becomes\;\;\;4y^2(2y-5)\)