Question

what is the sum of the last four terms of the series 35+30+25+...

Answer 1

20, 15, 10, and 5

Answer 2

wait, 5 is the last term?

Answer 3

yeah

Answer 4

you subtract 5 from the previous number every time

Answer 5

well, going backwards, you have:
\(\large\color{slate}{ 5,~10,~15,~20 }\)

so the sum (of last 4 terms) would be ?

Answer 6

thanks