Question

(2u+1)/(u+2)(u-3)

Answer 1

试想拆项吧,

设(2u+1)/(u+2)(u-3)=A/(u+2)+B/(u-3)=[(A+B)u+2B-3A]/(u+2)(u-3)

所以A+B=2,2B-3A=1

解得A=3/5,B=7/5

所以(2u+1)/(u+2)(u-3)=(1/5)[3/(u+2)+7/(u-3)]