1,10,31,70,133,( )A.136 B.186 C.226 D.256(請附上解題思路,謝謝!)
熱心網(wǎng)友
范進(jìn)中彩君的說法是對的,但可說得更規(guī)范,數(shù)列:^^ 1,10,31,70,133, 226,第一次差:9,21,39,63, 93,第二次差:^^ 12,18,24, 30, 為等差數(shù)列,所以,數(shù)列: 1,10,31,70,133, 226, 稱三階等差數(shù)列,
熱心網(wǎng)友
1^3+0=12^3+2=103^3+4=314^3+6=70,5^3+8=1336^3+10=226所以選D
熱心網(wǎng)友
1,10,31,70,133差:9,21,39,63即:3*3,3*7,3*13,3*21差的倍數(shù): 4, 6, 8......103*31+133=226