A/a+2+a/a-1=4a-1/(a+2)(a-1)成立则A等于多少

问题描述:

A/a+2+a/a-1=4a-1/(a+2)(a-1)成立则A等于多少

A/(a+2)+a/(a-1)=(4a-1)/(a+2)(a-1)
A(a-1)+a(a+2)=4a-1
aA-A+a^2+2a-4a+1=0
A(a-1)+(a-1)^2=0
A=-(a-1)^2/(a-1)
所以A=1-a