题目内容
1.化简或计算下列各式:(1)16${\;}^{-\frac{1}{2}}}$-(${\frac{1}{2}}$)${\;}^{-\frac{1}{2}}}$-(${\frac{27}{8}}$)${\;}^{\frac{2}{3}}}$+(${\frac{3}{5}}$)0+$\root{4}{{{{(1-\sqrt{2})}^4}}}$;
(2)(a${\;}^{\frac{2}{3}}}$b${\;}^{\frac{1}{2}}}$)×(-3a${\;}^{\frac{1}{2}}}$b${\;}^{\frac{1}{3}}}$)÷($\frac{1}{3}$a${\;}^{\frac{1}{6}}}$b${\;}^{\frac{5}{6}}}$).
分析 (1)化负指数为正指数,化0指数幂为1,整理后得答案;
(2)直接利用有理指数幂的运算性质化简得答案.
解答 解:(1)16${\;}^{-\frac{1}{2}}}$-(${\frac{1}{2}}$)${\;}^{-\frac{1}{2}}}$-(${\frac{27}{8}}$)${\;}^{\frac{2}{3}}}$+(${\frac{3}{5}}$)0+$\root{4}{{{{(1-\sqrt{2})}^4}}}$
=$({2}^{4})^{-\frac{1}{2}}-({2}^{-1})^{-\frac{1}{2}}-[(\frac{3}{2})^{3}]^{\frac{2}{3}}+1+\sqrt{2}-1$
=$\frac{1}{4}-\sqrt{2}-\frac{9}{4}+\sqrt{2}=-2$;
(2)(a${\;}^{\frac{2}{3}}}$b${\;}^{\frac{1}{2}}}$)×(-3a${\;}^{\frac{1}{2}}}$b${\;}^{\frac{1}{3}}}$)÷($\frac{1}{3}$a${\;}^{\frac{1}{6}}}$b${\;}^{\frac{5}{6}}}$)
=$-9{a}^{\frac{2}{3}+\frac{1}{2}-\frac{1}{6}}{b}^{\frac{1}{2}+\frac{1}{3}-\frac{5}{6}}=-9a$.
点评 本题考查有理指数幂的化简求值,是基础的计算题.
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