求等比数列1,3,9,27 …前6项和

2025-02-27 12:46:40
推荐回答(3个)
回答1:

解:
设构成等比数列{an}
a1=1,q=3/1=9/3=27/9=...=3
S6=a1(q⁶-1)/(q-1)
=1·(3⁶-1)/(3-1)
=364
等比数列前6项的和是364

回答2:

 

回答3:

364