-x+13/x-2x-15=(A/x-5)-(B/x+3)

问题描述:

-x+13/x-2x-15=(A/x-5)-(B/x+3)

(A/x-5)-(B/x+3)=[A(x+3)-B(x-5)]/(x^2-2x-15)=[(A-B)x+(3A+5B)]/(x^2-2x-15) 所以,A-B=-1,3A+5B=13.解得:A=1,B=2.