Answer:
40/m
Step-by-step explanation:
I dont really know what I'm answering but there's that
2x + 4x - 21 = 0
6x - 21 = 0
6x = 21
x=3.5
Answer: The required value of f(3) is 81.
Step-by-step explanation: We are given the following function :

We are to find the value of f(3).
Substituting x = 3 in equation (i), we get

Thus, the required value of f(3) is 81.