4x-1/(x+2)(x-1)=A/x+2 + x/x-1 则A等于 (A跟x的关系,)
问题描述：
4x-1/(x+2)(x-1)=A/x+2 + x/x-1 则A等于 (A跟x的关系,)
我要具体的过程 ,
我只知道4x-1=m（x-1）+x（x+2）接下来怎么办
答
(4x-1)/(x+2)(x-1)=A/(x+2)+x/(x-1)(4x-1)=[A/(x+2)+x/(x-1)]*(x+2)(x-1)(4x-1)=A(x-1)+x(x+2)A(x-1)=(4x-1)-x(x+2)A(x-1)=4x-1-x^2-2xA(x-1)=-x^2+2x-1A(x-1)=-(x-1)*(x-1)A=-(x-1) A=-x+1