已知1/x-1/y=3,求代数式5x+xy-5y除以x-xy-y的值.
问题描述:
已知1/x-1/y=3,求代数式5x+xy-5y除以x-xy-y的值.
答
(5x+xy-5y)/(x-xy-y)
=(5/y+1-5/x)/(1/y-1-1/x)
=(1-3)/(-1-3)
=1/2