Answer: y = 3x - 8
Step-by-step explanation:
1) A reflection over the x-axis keeps the x-coordinate and change the y-coordinate to -y. This is (x,y) → (x,-y)
2) Then, you can replace the new coordinates in the original equation, f(x) to get the equation of g(x):
-y = -3x + 8 ⇒ y = 3x - 8, which is the answer.