I got 21x +15 for my answer for this question using the triple product rule. why is it wrong?

Question 14 This question shows you how you can determine the derivative of a function without knowing its full formula. (It is a handy trick when your formula is very long and complex to write out.) 1 point How Did I Do? Set p (x) = If (x) g(x) , where f and g are differentiable functions that satisfy f (-3) = 3, f'( -3) = 3, 9 (-3) = 5 and g' (-3) = 2. Write down a formula for p (x) on paper. Using this and the information above, find the value of p (-3). Answer: P' (-3) = 21x+15 D