先化简,再求值(3a/a-1 -a/a+1)(a2-1/a),其中a=根号2-2

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先化简,再求值(3a/a-1 -a/a+1)(a2-1/a),其中a=根号2-2

先化简,再求值(3a/a-1 -a/a+1)(a2-1/a),其中a=根号2-2
先化简,再求值(3a/a-1 -a/a+1)(a2-1/a),其中a=根号2-2

先化简,再求值(3a/a-1 -a/a+1)(a2-1/a),其中a=根号2-2
原式=3a/(a-1)*(a+1)(a-1)/a-a(a+1)*(a+1)(a-1)/a
=3(a+1)-(a-1)
=3a+3-a+1
=2a+4
当a=√2-2 时,原式=2*(√2-2)+4
=2√2
答:所求式的化简结果为2a+4
当a=-2 时,求值结果为2√2 .

=[(3a²+3a-a²+a)/(a²-1)×(a²-1)/a
=2a+4
=2(√2-2)+4
=2√2

原式=[3a/(a-1)-a(a+1)](a+1)(a-1)/a
=3a/(a-1)*(a+1)(a-1)/a-a(a+1)*(a+1)(a-1)/a
=3(a+1)-(a-1)
=3a+3-a+1
=2(a+2)
=2(√2-2+2)
=2√2