To evaluate the function $f(x) = 3(-2x + 7)$ at $x = -7$, we substitute $-7$ for $x$ in the function and simplify.

$f(-7) = 3(-2(-7) + 7)$

Now, let's calculate step by step:

1. Multiply: $-2 \times -7 = 14$
2. Add: $14 + 7 = 21$
3. Multiply: $3 \times 21 = 63$

So, the final answer is:

$f(-7) = 63$

Would you like details on the steps, or do you have any other questions?

Here are some related questions:

1. How do you find the value of $f(x)$ for any $x$ in a linear function?
2. What are the properties of linear functions?
3. Can you graph the function $f(x) = 3(-2x + 7)$?
4. How would the answer change if the function was $f(x) = -2(3x - 7)$?
5. What is the slope and y-intercept of $f(x) = 3(-2x + 7)$?

Tip: Substituting values into functions is a key skill in algebra, useful in many problem-solving contexts.