先化简,再求值.2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2其中,a=根号2+1

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先化简,再求值.2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2其中,a=根号2+1

先化简,再求值.2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2其中,a=根号2+1
先化简,再求值.2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2其中,a=根号2+1

先化简,再求值.2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2其中,a=根号2+1
2/a-1+(a^2-4a+4)/(a^2-1)×a+1/a-2
=2/(a-1) +(a-2)²/(a+1)(a-1) ×(a+1)/(a-2)
=2/(a-1)+(a-2)/(a-1)
=a/(a-1)
当a=0时
原式=0
2.[1-(2/1-x)]÷(x+1)-x(x^2-1)/x^2-2x+1=(1-x-2)/(1-x) ×1/(x+1) -x(x+1)(x-1)/(x-1)²
=1/(x-1)-x(x+1)/(x-1)
=(1-x²-x)/(x-1)
=-(x²+x-1)/(x-1)
=0

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