Question

(1)2X+3)/(X-1)(X+2)=A/x-4+B/x+2,那A-B= (2)3X2-X=1,则6X3+7X2-5X

Answer 1

(1)

（2X+3)/(X-1)(X+2)=(2X-2+5)/(X-1)(X+2)=5/3(X-1)+1/3(x+2)

由A/x-1=5/3(X-1) B/x+2= 1/3(x+2)

A=5/3 B=1/3 A-B=4/3

(2)

6X3+7X2-5X+2008=6X3-2X2+9X2-5X+2008

=2X(3X2-X)+9X2-5X+2008

=2X+9X2-5X+2008

=3(3X2-X)+2008

=3+2008

=2011