Question

求下列各數(shù)的和：，，．

Answer 1

【答案】分析：根據(jù)負(fù)整數(shù)指數(shù)冪、絕對值、零指數(shù)冪、二次根式等知識點進(jìn)行解答．
解答：解：由題意得：
++
=-×2+×1+
=-1++
=．
點評：非0數(shù)的負(fù)指數(shù)次冪是正指數(shù)次冪的倒數(shù)，它的0次冪是1．