what is the sum of the first 29 terms of the arithmetic sequence? -43,-35,-27,-19,...
The 29th term is given by :
1st term + common difference * ( 29 - 1) =
-43 + 8*(28) = 181
The sum is given by
[ 1st term + 29th term ] * number of terms / 2 =
[ -43 + 181 ] * 29 / 2 =
[ 138 ] * 29 / 2 =
2001
