How do you find three consecutive odd positive integers such that 3 times the sum of all three is 24 more than the product of the first and second integers?

1 Answer
Mar 16, 2016

{1, 3, 5}

Explanation:

Any odd number may be represented as 2k+1 for some integer k. Then, let's represent our odd integers as 2k+1, 2k+3, 2k+5 where k is a non-negative integer. From our initial condition, we have that

(2k+1)(2k+3)+24 = 3((2k+1)+(2k+3)+(2k+5))

Simplifying both sides, we get

4k^2+8k+27 = 18k+27

=> 4k^2-10k = 0

=> 4k(k-5/2) = 0

=> k = 0 or k = 5/2

But, as we specified that k must be an integer, we know that k!=5/2. Thus we have k = 0 and so our odd integers are {1, 3, 5}

Checking this, we find that 1*3+24 = 27 = 3(1+3+5)