因为4a-1/(a+2)(a-1)=m/(a+2) + n/(a-1),且m/(a+2) + n/(a-1)=m(a-1)+n(a+2)/(a+2)(a-1) 所以4a-1/(a+2)(a-1)=m(a-1)+n(a+2)/(a+2)(a-1) 所以4a-1=m(a-1)+n(a+2) =ma-m+na+2n =a(m+n)-(m-2n) 所以4=m+n 1=m-2n m=4-n...