(2011四川内江,6分)若,则的值是 .
(2011台湾全区,17)17.计算之值为何?
A. B. C. D.
(2011台湾台北,4)计算+之值为何?
A.5 B.3 C.3 D. 9
(2011湖南衡阳,11,3分)计算 .
(2011山东聊城,13,3分)化简:=_____________.
(2011江苏南通,12,3分)计算:= ▲ .