Question

先化简再求值,x²-2x+1分之x²-1+x-2分之x²-2x÷x,其中x=根号5+1

Answer 1

(x^2-1)/(x^2-2x+1)+(x^2-2x)/(x-2)÷x

=[(x+1)(x-1)]/(x-1)^2+x(x-2)/(x-2)X1/x

=(x+1)/(x-1)+1

=2x/(x-1)

因为x=根号5+1

所以原式=2（根号5+1）/(根号5+1-1)

=2/5倍（5+根号5）