约分 (x-y)(a-b)2/(x2-y2)(b-a)
问题描述:
约分 (x-y)(a-b)2/(x2-y2)(b-a)
答
(x-y)(a-b)2/(x2-y2)(b-a)
=2(x-y)(a-b)/-2(x-y)(a-b)
=-1