The expressions \(2n - 1\) and \(2n + 1\) can ... but to prove that it is true all the time we must use algebra. Write the first of the two even numbers as \(2n\), where \(n\) is an integer.

In algebra, letters are used to stand for values that can change (variables) or for values that are not known (unknowns). A term is a number or letter on its own, or numbers and letters multiplied ...

Parsing algebraic expressions is always a pain. If you need to compute, say, 2+4*2, the answer should be the same as (2 + (4 *2)), not ((2 + 4) * 2) — in other words, the right answer is 10 ...

The formal expression of this relationship is: Since each of these operations can be derived from one another, only one is needed as the second rule in the switching algebra. The AND and OR ...