1. Problem: Evaluate the function $f(x) = -3x + 4$ at $x=4$. 2. Formula: To find $f(a)$, substitute $x$ with $a$ in the function. 3. Calculation: $$f(4) = -3(4) + 4 = -12 + 4 = -8$$ 4. Explanation: We replaced $x$ with 4, multiplied by -3, then added 4 to get the result. Final answer: $f(4) = -8$