先化简,再求值 x+3/x2-1 ÷(x+3)(x-1)/x2-2x+1,其中x=2007,
问题描述：
先化简,再求值 x+3/x2-1 ÷(x+3)(x-1)/x2-2x+1,其中x=2007,
答
有很多种的~
答
(x+3)/(x²-1) ÷(x+3)(x-1)/(x²-2x+1)=(x+3)/(x-1)(x+1) ÷(x+3)(x-1)/(x-1)²=(x+3)/(x-1)(x+1) ÷(x+3)/(x-1)=(x+3)/(x-1)(x+1) ×(x-1)/(x+3)=1/(x+1)=1/(1+2007)=1/2008