SOLUTION: find the sum of the terms of the arithmetic sequence1,7,13,19,...109 n = 19

Algebra ->  Test -> SOLUTION: find the sum of the terms of the arithmetic sequence1,7,13,19,...109 n = 19      Log On


   

Question 724411: find the sum of the terms of the arithmetic sequence1,7,13,19,...109 n = 19
Found 2 solutions by mananth, stanbon:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
First term = 1
difference = 6
n=19
Sn= 2a+(n-1)d
S19=2+18*6
=2+108
=110

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
find the sum of the terms of the
arithmetic sequence1,7,13,19,...109; n = 19
------
S(19) = (19/2)(1+109) = (19)(55) = 1045
====================
Cheers,
Stan H.
====================