Question

I don't want the answer, just need to know how to do it? Help?
"What is the sum of a 52–term arithmetic sequence where the first term is 1 and the last term is 154?"

Answer 1

You could work out what the common difference is, then use the finite sequence sum formula.

\[\large s_n = \frac{n(t_1 + t_n)}{2}\]

Answer 2

Actually, I guess you could skip the first step. Sn is the sum of n terms. t_1 is the first term and t_n is the nth term. n is the number of terms.

Answer 3

So would n=154?

Answer 4

OH! so x=154(155)/2?

Answer 5

No. It says there are 52 terms so n = 52.

Answer 6

So you aren't adding 1+2+3+4+...154.
You are adding \[1+t_2+t_3+t_4+... + t_{49}+t_{50}+t_{51}+154\]

Answer 7

So...if I'm correct.
(52/2)(154+1)?

Answer 8

then, 26*155? =4030?

Answer 9

good.