题目内容
计算：（每小题6分，共24分）
(1) 
(2) 
(3) 
(4) 
（1）
（2）-16
（3）-49
（4）-19
解析:
(1) 解：原式
····································································· 1分
································································ 2分
··········································································· 4分
·················································································· 6分
(2) 解：原式
························································· 1分
······························································ 4分
·········································································· 5分
················································································ 6分
(3) 解：原式
·························································· 3分
······································································ 4分
················································································ 6分
(4) 解：原式
···················································· 2分
······························································ 3分
····································································· 4分
··········································································· 5分
··············································································· 6分
（2）
（4）
； （2）
．
