问题描述: 若a满足条件a^2+2a-1=0,则(a-2/a^2+2a-a-1/a^2+4a+1)除以a-4/a+2=_____. 1个回答 分类:数学 2014-10-09 问题解答: 我来补答 因为a^2+2a-1=0,所以a^2+2a=1,所以[(a-2)/(a^2+2a)-(a-1)/(a^2+4a+4)]/[(a-4)/(a+2)=[(a-2)/a(a+2)-(a-1)/(a+2)^2]*[(a+2)/(a-4)]=[(a-2)(a+2)/a(a+2)^2-a(a-1)/a(a+2)^2]*[(a+2)/(a-4)]=[(a^2-4-a^2+a)/a(a+2)^2]*[(a+2)/(a-4)]=[(a-4)/a(a+2)^2]*[(a+2)/(a-4)]=1/a(a+2)=1/(a^2+2a)=1/1=1. 展开全文阅读