解:(1)原式=1+1-3+2
=1;
(2)原式=(9
+
-2
)÷4
=8
÷4
=2;
(3)原式=
=
+
=6+2
;
(4)原式=4
-
+3-
-1-2+
=3
.
分析:(1)先算正整數(shù)指數(shù)冪、零指數(shù)冪、負(fù)整數(shù)指數(shù)冪和根式,再合并同類項(xiàng);
(2)先算括號(hào)里面的二次根式,再合并同類項(xiàng),然后算括號(hào)外面的除法;
(3)將分子和分母同時(shí)乘以(
+
),再根據(jù)乘法分配律計(jì)算分子,化簡(jiǎn)合并同類項(xiàng);
(4)先算二次根式、負(fù)整數(shù)指數(shù)冪、零指數(shù)冪和絕對(duì)值,再合并同類項(xiàng).
點(diǎn)評(píng):(1)本題主要考查正整數(shù)指數(shù)冪、零指數(shù)冪、負(fù)整數(shù)指數(shù)冪和根式的混合運(yùn)算;
(2)本題主要考查二次根式的混合運(yùn)算,二次根式的運(yùn)算結(jié)果要化為最簡(jiǎn)二次根式;
(3)本題也是考查二次根式的混合運(yùn)算,二次根式的運(yùn)算結(jié)果要化為最簡(jiǎn)二次根式;
(4)本題主要考查二次根式、負(fù)整數(shù)指數(shù)冪、零指數(shù)冪和絕對(duì)值的混合運(yùn)算.