问几个数列题(1) 1,2,3/2,8/3,15/8,( )A.53/15 B.52/15 C.49/15 D.48/15(2) 13,17,26,( ),69,105A.28 B.36 C.42 D.45(3) 5,7,4,9,25,( )A.168 B.216 C.256 D.296(4) ( ),35,63,80,99,143A.24 B.15 C.13 D.1(5) 3,18,60,147,( )A.297 B.300 C.303 D.307(6) 1/2,1,4
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问几个数列题(1) 1,2,3/2,8/3,15/8,( )A.53/15 B.52/15 C.49/15 D.48/15(2) 13,17,26,( ),69,105A.28 B.36 C.42 D.45(3) 5,7,4,9,25,( )A.168 B.216 C.256 D.296(4) ( ),35,63,80,99,143A.24 B.15 C.13 D.1(5) 3,18,60,147,( )A.297 B.300 C.303 D.307(6) 1/2,1,4
问几个数列题
(1) 1,2,3/2,8/3,15/8,( )
A.53/15 B.52/15 C.49/15 D.48/15
(2) 13,17,26,( ),69,105
A.28 B.36 C.42 D.45
(3) 5,7,4,9,25,( )
A.168 B.216 C.256 D.296
(4) ( ),35,63,80,99,143
A.24 B.15 C.13 D.1
(5) 3,18,60,147,( )
A.297 B.300 C.303 D.307
(6) 1/2,1,4/3,19/12,( )
A.133/60 B.137/60 C.107/60 D.147/60
问几个数列题(1) 1,2,3/2,8/3,15/8,( )A.53/15 B.52/15 C.49/15 D.48/15(2) 13,17,26,( ),69,105A.28 B.36 C.42 D.45(3) 5,7,4,9,25,( )A.168 B.216 C.256 D.296(4) ( ),35,63,80,99,143A.24 B.15 C.13 D.1(5) 3,18,60,147,( )A.297 B.300 C.303 D.307(6) 1/2,1,4
DCCBAC
1,先确定分母是15,再相邻两项相乘得到关系,就得到分子
2,貌似有点问题,我怀疑是不是69应该是67,然后105就是103
3,4=(7-5)^2,9=(4-7)^2,25=(9-4)^2
4,35=6^2-1,63=8^2-1,80=9^2-1,99=10^2-1,143=12^2-1
6,8,9,12应该是合数的关系,那么之前的就是4
5,无规律,应该就只有四级等差
6,后项减前项就可以看出规律了