已知2/x(x2-1）=(A/x)+(B/x+1)+(C/x-1),求A,B,C,的值

2/(X(X^2-1))=A/X+B/(X+1)+C/(X-1)=(A(X-1)(X+1)+BX(X-1)+CX(X+1))/(X(X^2-1))
=(AX^2-A+BX^2-B+CX^2+C)/(X(X^2-1))
则有 A+B+C=0
C-A-B=2
==> C=1 A+B=-1