1. The problem involves evaluating the function $f(x) = -4x - 8$ at $x = -3$. 2. The formula for evaluating a function at a given input is $f(a) = \text{expression with } x \text{ replaced by } a$. 3. Substitute $x = -3$ into the function: $$f(-3) = -4(-3) - 8$$ 4. Simplify the multiplication: $$f(-3) = 12 - 8$$ 5. Perform the subtraction: $$f(-3) = 4$$ 6. Therefore, the value of the function $f(x) = -4x - 8$ at $x = -3$ is $4$. This means when you input $-3$ into the function, the output is $4$.