若b分之a=2,则a²+b²分之a²-ab+b²=

问题描述:

若b分之a=2,则a²+b²分之a²-ab+b²=

a/b=2
a=2b
∴ ﹙a²-ab+b²﹚/﹙a²+b²﹚
=﹙4b²-2b²+b²﹚/﹙4b²+b²﹚
=3b²/5b²
=3/5谢谢,答案是对的,再问你一道题,已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值﹙2x+3xy-2y﹚/﹙x-2xy-y﹚ =[2﹙x-y﹚+3xy]/[﹙x-y﹚-2xy] =﹙8xy+3xy﹚/﹙4xy-2xy﹚ =11xy/2xy =11/2.