Question

(x的2次方-xy-2(y)的2次方)分之(x的2次方-y的2次方)=( )分之(x-y)

Answer 1

解

(x²-y²)/(x²-xy-2y²)

=(x-y)(x+y)/(x-2y)(x+y)

=(x-y)/(x-2y)

=(x-2y)分之(x-y)