The function provided is $f(x) = -7x$. To find $f(1)$, substitute $x = 1$ into the function:

$f(1) = -7(1) = -7$

Thus, $f(1) = -7$.

Would you like more details, or do you have any questions?

Here are some related questions to expand your understanding:

1. What would $f(2)$ be using the same function rule?
2. How would you find $f(x)$ for a general value of $x$?
3. What kind of function is $f(x) = -7x$ (linear, quadratic, etc.)?
4. How does the slope of this linear function affect the graph?
5. What is the value of $f(-1)$ in this function?

Tip: Linear functions like $f(x) = -7x$ have a constant rate of change, which is represented by the slope (in this case, $-7$).