Answer:
The value of f(12) and f(14) are 36 and 42 respectively
Explanation:
Given function

we have to find the values of f(12) and f(14)
To find f(12)
Put x=12 in given function y=3x

To find f(14)
Put x=14 in given function y=3x

The value of f(12) and f(14) are 36 and 42 respectively