7 11 19 27 39 51 67
7 11 19 27 39 51 67
例题:7,11,19,27,39,51,67,() A.76 B.87 C.82 D.79
7,19,39,67,103,计算规律
六年级简算3/7+7/11+11/15+15/19+19/23+23/27+27/31+31/35+35/39+39/4
2 3 5 7 11 13 17 19 23 29 31 37 41 13 47 51 53 59 61 67 71 7
13 8 11 43 37 39 51 93 1 62 99 61 57 27 2 19 质数:合数:既不是质数也不是合
找规律5,7,11,19,35,67
找规律:5 7 11 19 35 67 () ()
5 7 11 19 35 67 .规律公式
[(17*27+7)/27+(27*17+7)/17-(11*39+37)/39]/[(8*27+17)/27+(13*
4 16 18 19 22 32 34 40 3 5 7 9 11 13 17 19 3 18 27 45 51 53
1,2,3,4,5,7,9,11,15,21,27,29,39,41,46,51,46哪些素数,哪些合数?