Question

check answer @jim_thompson5910

Answer 1

420

Answer 2

nope.....

Answer 3

aw man. :(

Answer 4

i did it again and got the same answer...?

Answer 5

Use the formula for arithmetic series

Answer 6

wait, no i figured out where i was making the mistake.

Answer 7

168

Answer 8

just plug values in equation of finding the sum of a AP
S = \[\frac{ n }{ 2 }[2a_1 + (n - 1)d]\]
just plug the values

Answer 9

Sum of the first n terms of an arithmetic sequence
\[\Large S_n = \frac{n*(a_1 + a_n)}{2}\]

\(\Large a_1\) is the first term
\(\Large a_n\) is the nth term
\(\Large a_n = a_1 + d(n-1)\) where d is the common difference

Answer 10

The formula I posted leads to what rishavraj posted after you plug in \(\Large a_n = a_1 + d(n-1)\) and simplify a bit

Answer 11

\(\color{blue}{\text{Originally Posted by}}\) @StudyGurl14
168
\(\color{blue}{\text{End of Quote}}\)
Nope

Answer 12

....darn

Answer 13

The answer is less important than understanding the method

Answer 14

10+(17-1)(4) = 74
\(\large\frac{4(10+74)}{2}=168\)
@Miracrown

Answer 15

that '4' should be '17' (since it's the value of n)

Answer 16

@StudyGurl14 its
\[\frac{ 17 }{ 2 }[20 + (16)4]\]

Answer 17

oh, oops. ...lol....

Answer 18

What they said

Answer 19

4 is the rate, not the term. my mistake

Answer 20

you confused n with d

Answer 21

714?

Answer 22

Yesh

Answer 23

thanks everyone.