题目内容
16.化简、求值:(1)(2a${\;}^{\frac{1}{4}}$b-${\;}^{\frac{1}{3}}$)(-3a-${\;}^{\frac{1}{2}}$b${\;}^{\frac{2}{3}}$)÷(-$\frac{1}{4}$a-${\;}^{\frac{1}{4}}$b-${\;}^{\frac{2}{3}}$)
(2)(log43+log83)(log32+log92)-log${\;}_{\frac{1}{2}}$$\root{4}{32}$.
分析 (1)根据同底数的幂的称出运算法则进行计算即可;
(2)根据对数的运算法则进行计算即可.
解答 解:(1)(2a${\;}^{\frac{1}{4}}$b-${\;}^{\frac{1}{3}}$)(-3a-${\;}^{\frac{1}{2}}$b${\;}^{\frac{2}{3}}$)÷(-$\frac{1}{4}$a-${\;}^{\frac{1}{4}}$${b}^{-\frac{2}{3}}$)
=2×(-3)×(-4)${a}^{\frac{1}{4}-\frac{1}{2}+\frac{1}{4}}$•${b}^{-\frac{1}{3}+\frac{2}{3}+\frac{2}{3}}$
=24b;
(2)(log43+log83)(log32+log92)-log${\;}_{\frac{1}{2}}$$\root{4}{32}$
=($\frac{lg3}{2lg2}$+$\frac{lg3}{3lg2}$)($\frac{lg2}{lg3}$+$\frac{lg2}{2lg3}$)-$\frac{\frac{1}{4}lg32}{lg\frac{1}{2}}$
=$\frac{5}{6}$•$\frac{lg3}{lg2}$•$\frac{3}{2}$•$\frac{lg2}{lg3}$-$\frac{\frac{5}{4}lg2}{-lg2}$
=$\frac{5}{4}$+$\frac{5}{4}$
=$\frac{5}{2}$.
点评 本题考查了指数与对数的运算问题,是基础题目.
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