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问题: 初二数学

已知a=√3-√2求(a^2+2a+1)/(a^3-a)-2/(a-1)
^为几次方

解答:

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