# Arithmetic Sequences Problem

• November 30th 2011, 07:12 AM
MalevolentSpoon
Arithmetic Sequences Problem
"Find three consecutive terms of an arithmetic sequence if their sum is 3 and their product is -15"

I know the answer is -3,1,5 but I pretty much just guessed that on a fluke. What is the method of answering this question? I don't think I'll get the marks unless I use a method of some sort :(
• November 30th 2011, 07:35 AM
Quacky
Re: Arithmetic Sequences Problem
Let $a$, $(a+d)$, and $(a+2d)$ be the three consecutive terms, where $d$ is the common difference. Set up simultaneous equations for $a$ and $d$.
• November 30th 2011, 11:22 AM
MalevolentSpoon
Re: Arithmetic Sequences Problem
Quote:

Originally Posted by Quacky
Let $a$, $(a+d)$, and $(a+2d)$ be the three consecutive terms, where $d$ is the common difference. Set up simultaneous equations for $a$ and $d$.

Thanks! It makes sense now :)