Answer:
Her son is 14 years old
Step-by-step explanation:
5+3x=47
3x=47-5
3x=42
3x÷3=42÷3
x=14
As this is a trinomial function I believe the answer is true due to the fact that a trinomial curve consists of three parabolic curves in which each has its own respective minimum or maximum value i.e. critical number.