【判断题】Management is to coordinat e work activities so that they are completed efficiently and effectively.
【单选题】65÷3=21…2,正确的验算的方法是( )
【简答题】约分: 7 a 2 b 2 -21a b 2 =______.
【简答题】如果 ( 3 +2x ) 21 = a 0 + a 1 x+ a 2 x 2 +…+ a 21 x 21 ,那么(a 1 +a 3 +a 5 +…+a 21 ) 2 -(a 0 +a 2 +a 4 +…+a 20 ) 2 等于( ) A.1 B.-1 C.2 D.-2
【单选题】因为65÷3=21…2,所以650÷30的正确结果是多少?( )