Math Is Fun Forum
Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2008-02-26 11:00:28
- Joseph
- Guest
6th grade math
Find 3 integers whose product is -36 and whose sum is 5.
#2 2008-02-26 11:04:51
- mathsyperson
- Moderator
- Registered: 2005-06-22
- Posts: 4,900
Re: 6th grade math
6, 2, -3.
Just by trying stuff though, I can't think of a way to reason an answer.
Why did the vector cross the road?
It wanted to be normal.
Offline
#3 2008-02-27 02:35:46
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: 6th grade math
An alternative to reasoning an answer is to use Excel. 
Let the integers be a, b, c with a ≤ b ≤ c. Their product must be −36. So try all possible combinations for a, b, c (I make it there are only 28 of them) and for each combination, check their sum. There is indeed only one combination that gives a+b+c = 5.
Offline
Pages: 1