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

题目

(2u+1)/(u+2)(u-3)
因式分解

答案

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)]