Answer:
Explanation:
Whenever there is a question asking to find something like f(7), it is asking you to substitute the number within those parentheses for the matching variable within the function.
To find f(7), first substitute 7 for all the x's within the function. Then, following PEMDAS, simplify like how you normally would. Multiply out
, then multiply 3 by 7, then add all the numbers together.
Thus,
.