Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

Login

Username

Password

Not registered yet?

Post a reply

Go back

Write your message and submit
:) :| :( :D :o ;) :/ :P :lol: :mad: :rolleyes: :cool: | :dizzy :eek :kiss :roflol :rolleyes :shame :down :up :touched :sleep :wave :swear :tongue :what :faint :dunno
Options

Go back

Topic review (newest first)

bob bundy
2013-09-06 16:42:05

hi Ani

Welcome to the forum.

From that information and with subtraction, you can say what the sixth term is.

There are two formulas that can be used:



and



So you can make two simultaneous equations in a and d.

Bob

Ani
2013-09-06 16:41:25

Thank you smile

Fruityloop
2013-09-06 13:50:27

Use the difference between the sums to head towards an answer.

Ani
2013-09-06 12:24:32

I've been sitting for a few hours thinking how to figure out the question below, could you help me solve this in a step-by-step format?

The Question;
The sum of the first five terms of an arithmetic series is 85. The sum of the first six terms is 123. What are the first four terms of the series?

Thank you for any help

Board footer

Powered by FluxBB