Question

(a²-1)/a-1 - √a²-2a+1/a²-a化简,并算出当a=2-√3 时,结果为

Answer 1

原式=（a+1）（a-1）/(a-1 ) -√(a-1)²/a(a-1)

=a+1-(1-a)/a(a-1)

=a+1+1/a

=2-√3+1+1/(2-√3)

=3-√3+(2+√3)/(2-1)

=3-√3+2+√3

=5

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