(1) If f(x) = 3x + 5 and g(x) = x - 3, then f(2) + g(5) =

(2) Given f(x) = x^2 - x + 3 and g(x) = 5x + 7, find f(g(2))

(3) Find a and b in f(x) = ax + b, if f(2)=7 and f(4) = -7.