Simple Functional Relationships Practice Test

The function $$q(x) = |x - 4|$$ is graphed below. For which value of $$x$$ is $$q(x) = q(x + 2)$$?

A function $$f$$ is defined such that $$f(x) = 2x + 3$$ for all real numbers $$x$$. If $$f(a) = 15$$, what is the value of $$f(a - 2)$$?