If f(x) = x + 2, what is f(x) − 2?

Correct answer: x

The governing concept is substitution followed by algebraic simplification of a function expression. Since f(x) = x + 2, replace f(x) in the requested expression with x + 2. This gives f(x) − 2 = (x + 2) − 2. The constants +2 and −2 cancel, leaving x. Therefore option A is correct. Option B adds 2 instead of subtracting it, option C incorrectly doubles the variable, and option D subtracts 2 from x even though the function already contains +2 that must also be included. The result is an identity: for every value of x in the domain, evaluating f(x) and then subtracting 2 returns the original input x.