计算x的平方-y的平方/xy-(xy-y的平方)/(xy-x的平方)
问题描述:
计算x的平方-y的平方/xy-(xy-y的平方)/(xy-x的平方)
答
原式=x^2/xy-y^2/xy-[(x-y)y]/[(y-x)x]
=x/y-y/x+y/x
=x/y.