Question

y²分之（x²-2xy+y²）除以xy分之（y²-xy）乘xy²,其中x=4,y=3.

Answer 1

（x²-2xy+y²)/y²÷（y²-xy）/xy *xy²

=(x-y)²/y²*xy/(y²-xy) *xy²

=(x-y)²*xy/y(y-x) *x

=(y-x)*x²

=(3-4)*4²

=-16