Answer
15
Work Step by Step
We are given that $f(x)=3x+3$.
$f(4)=3\times4+3=12+3=15$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.