数学高手来啊！！！！！不会啊！！！！！！！急！！！！！！！

Question

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Answer 1

X=1/(√3+2) =(2-√3)

原式的第一项
=(x^2-x)/(√(x^2-2x+1))
=[x(x-1)]/[√(x-1)^2]
由于x-1=(2-√3)-1=(1-√3)<0
故√(x-1)^2=-(x-1)
故上式
=[x(x-1)]/[-(x-1)]
=-x

原式的第二项
=(1-2x+x^2)/(x-1)
=(x-1)^2/(x-1)
=x-1

故原式
=-x-(x-1)
=-2x+1
=-2*(2-√3)+1
=2√3-3

Answer 2

x=1/(√3+2)=2-√3<1;
1-x>0
(x^2-x)/√x^2-2x+1-（1-2x+x^2)/(x-1)
=x(x-1)/√(1-x)^2-(1-x)^2/(x-1)
=-x+1-x
=-2x+1
=-2(2-√3)+1
=2√3-3

Answer 3

答案