按规律填数.(1)21,18,15,( ),( ),6,( ),0.(2)3,9,27,81,( ),( ),( ).

问题描述:

按规律填数.(1)21,18,15,( ),( ),6,( ),0.(2)3,9,27,81,( ),( ),( ).
按规律填数.
(1)21,18,15,( ),( ),6,( ),0.
(2)3,9,27,81,( ),( ),( ).
(3)3,1,3,4,3,9,3,16,3,( ),( ).

按规律填数.(1)21,18,15,( 12 ),( 9 ),6,( 3 ),0.
(2)3,9,27,81,( 243 ),( 729 ),( 2187 ).
(3)3,1,3,4,3,9,3,16,3,(25 ),( 3 ).