First, let's consider the nature of integers. The integers are ... , -3, -2, -1, 0, 1, 2, 3, .... Even and odd numbers have been discussed since antiquity. To be even, a number must be divisible by 2, and the term odd refers to those numbers that are not divisible by two. So, a number dichotomy is created by even and odd that can be used to separate the integers into two sets: the evens and the odds. The even integers are ... -4, -2, 0, 2, 4, .... By definition, all of the even integers can be represented as multiples of 2. Starting with any even integer, we may generate a list of consecutive even integers beyond it by adding or subtracting two, repeatedly. For example, starting with 18, we get a list of consecutive even integers by writing
18, 18 + 2, 18 + 2 + 2, 18 + 2 + 2 + 2, ... and so on. Using this information, and a little ingenuity, the problem of finding the set of consecutive even integers fitting given constraints can now be solved. However, using algebraic techniques can help you avoid trial and error. Looking back at the list we generated from 18, we see that the list may also be written 2(9), 2(9 + 1), 2(9 + 2), 2(9 + 3), .... Now, start an unknown integer, n. How do you generate a list of unknown, but consecutive even integers with n? Once you do that, all that remains is to construct an equation that represents the constraints in the given problem. The solution to that equation will the integer you need to find the three consecutive integers in question.