关于初中的数学计算（过程）

(x^2-2x/x^2-1)/[(x-1)-(2x-1/x+1)]
=(x^2-2x/x^2-1)/[(x^2-1)/(x+1)-(2x-1)/(x+1)]
=(x^2-2x/x^2-1)/[(x^2-1-2x+1)/(x+1)]
=(x^2-2x/x^2-1)*(x+1)/(x^2-2x)
1/(x-1)

当x=1/2时
原式=1/（1/2-1）
=-2

（2） (3/x-1)+(2x/x+1)=2
方程两边同乘以（x-1)(x+1)
得3(x+1)+2x(x-1)=2(x+1)(x-1)
化简之后结果为x=5

好难哦 鬼才会做

(1)
(x^2-2x)/(x^2-1)÷ [x-1- (2x-1)/(x+1)]
=(x^2-2x)/[(x+1)(x-1)]÷{[(x-1)(x+1)-(2x-1)]/(x+1)}
=(x^2-2x)/[(x+1)(x-1)]÷[(x^2-2x)/(x+1)]
=(x^2-2x)(x+1)/[(x+1)(x-1)(x^2-2x)]
=1/(x-1)
1/(1/2-1)=-2
(2) ……麻烦

去分母x=-5