Question

好人来，小弟求答！先化简，再求值:(X-1)分之X-(X+1)分之X除以(1-X)分之2X，其中X等于根号3。

Answer 1

X/(X-1)-X/(X+1)÷2X/(1-X)
=X/(X-1)+(2X^2)/[(X+1)(X-1)]
=[X(X+1)]/[(X+1)(X-1)]+(2X^2)/[(X+1)(X-1)]
=(3X^2+X)/[(X+1)(X-1)]
=(3X^2+X)/(X^2-1)
当X=根3时
原式=（9+√3）/(3-1)=9/2+√3/2.

Answer 2

解：原式=x/(x-1)-(1-x)/2x+2
=x(1-x)/[(x-1)(2x+2)]
=(x²-x)/(2x²-2x-3)
当x=√3时，x²=3，原式=（3-√3）/（2*6-2*√3-3）
=（3-√3）/（9-2√3）
答：所求式的值为（3-√3）/（9-2√3）

Answer 3

=x/(x-1)-x/(x+1)×(1-x)/2x
=x/(x-1)+(x-1)/2(x+1)
=[2x(x+1)+(x-1)²]/2(x-1)(x+1)
=(3x²+1)/2(x²-1) x²=3
=(9+1)/2(3-1)
=5/2

Answer 4

答案是负二分之一

Answer 5

2分之1-根号3