解:依题意,a/(x+1)+b/(x+2)=[a(x+2)+b(x+1)]/[(x+1)(x+2)]=[(a+b)x+2a+b)/[(x+1)(x+2)]=(2x+1)/[(x+1)(x+2)] ∴a+b=2 希望能帮到你O(∩_∩)O哈哈~如果满意谢谢采纳哦。
(2x+1)/(x+1)(x+2)=A/(x+1)+B/(x+2) 通分得分子相等有 2x+1=(A+B)x+2A+B 有2=(A+B) 1=2A+B 解得A=1 B=-1 A+B=0