3、找规律填空
(1)47,43,39,35,(),(),()
(2)1,4,16,64,(),()
(3)60,50,(),(),20,()
(4)4,8,10,10,16,12,(),(),()
答案与解析:
(1)等差数列,公差为4,填31,27,23
(2)前一项乘以4得后一项,是等比数列,填256,1024
(3)等差数列,公差为10,填40,30,10
(4)双重数列,填22,14,28