考點(diǎn):對(duì)數(shù)的運(yùn)算性質(zhì),有理數(shù)指數(shù)冪的化簡(jiǎn)求值
專題:函數(shù)的性質(zhì)及應(yīng)用
分析:(1)利用指數(shù)的性質(zhì)和運(yùn)算法則求解.
(2)利用對(duì)數(shù)的性質(zhì)和運(yùn)算法則求解.
(3)利用對(duì)數(shù)的性質(zhì)和運(yùn)算法則求解.
解答:
解:(1)(0.25)
-0.5-(
)
- +16
0.25=2-3+2
=1.
(2)lg25+lg2•lg50+(lg2)
2=2lg5+lg2(lg2+2lg5)+(lg2)
2=2lg5+2lg2•lg5+2(lg2)
2=2lg5+2lg2
=2.
(3)
=
(1-lg3)(lg3+3lg2-) |
lg0.3•lg1.2 |
=-
×
=-
.
點(diǎn)評(píng):本題考查指數(shù)、對(duì)數(shù)的化簡(jiǎn)求值,是基礎(chǔ)題,解題時(shí)要認(rèn)真審題,注意指數(shù)、對(duì)數(shù)的性質(zhì)和運(yùn)算法則的合理運(yùn)用.