化简：（1/X+1）-（X+3/X^2-1）÷（（X+3）*（X+1）/(X^2_2X+1)）
问题描述：
化简：（1/X+1）-（X+3/X^2-1）÷（（X+3）*（X+1）/(X^2_2X+1)）
答
（1/X+1）-（X+3/X^2-1）÷（（X+3）*（X+1）/(X^2-2X+1)）=1/(x+1)-(x+3)/(x-1)(x+1)÷[(x+3)*(x+1)/(x-1)^2=1/(x+1)-(x+3)/(x-1)(x+1)*(x-1)^2/(x+3)*(x+1)=1/(x+1)-1/(x+1)*(x-1)/(x+1)=1/(x+1)-(x-1)/(x+1)^2=(x...