You have linear functions f(x) and g(x). You know f(2)=3, and f(g(x))=4x+7 for all x. Find g(-1).
f(2) = 3
f(g(-1)) = 4(-1) + 7 = 3 = f(2)
Because f(g(-1)) = f(2), g(-1) = 2.
