- y5−y4=y4(y−1)y5−y4=y4(y−1){y}^{5}{ }{-}{ }{y}^{4}{ }{=}{ }{y}^{4}{(}{y}{ }{-}{ }{1}{)}
- y5−y4=y3(y2−1){y}^{5}{ }{-}{ }{y}^{4}{ }{=}{ }{y}^{3}{(}{y}^{2}{ }{-}{ }{1}{)}
- y5−y4=y5(1−y){y}^{5}{ }{-}{ }{y}^{4}{ }{=}{ }{y}^{5}{(}{1}{ }{-}{ }{y}{)}
- y5−y4=y4(y+1){y}^{5}{ }{-}{ }{y}^{4}{ }{=}{ }{y}^{4}{(}{y}{ }{+}{ }{1}{)}