x+1分之A加x-1分之B=(x+1)(x-1)分之x-3
[A(X-1)+B(X+1)]/(X+1)(X-1)=(x-3)/(X+1)(X-1)
所以
A(X-1)+B(X+1)=x-3
(A+B)x+(A-B)=X-3
所以
A+B=1
A-B=3
解得
A=2,B=-1
x+1分之A加x-1分之B=(x+1)(x-1)分之x-3
[A(X-1)+B(X+1)]/(X+1)(X-1)=(x-3)/(X+1)(X-1)
所以
A(X-1)+B(X+1)=x-3
(A+B)x+(A-B)=X-3
所以
A+B=1
A-B=3
解得
A=2,B=-1