按规律填空2,6,12,( ) ,( ),42,56
问题描述：
按规律填空2,6,12,( ) ,( ),42,56
答
2=1x2,6=2x3,12=3x4,(20 )=4x5 ,(30 )=5x6,42=6x7,56=7x8
按规律填空2,6,12,( ) ,( ),42,56
2=1x2,6=2x3,12=3x4,(20 )=4x5 ,(30 )=5x6,42=6x7,56=7x8