Suppose a parabola has its axis of symmetry at $x=13$, has a vertical stretch of 4, opens downward, and has its vertex at the point $(13 ,-17)$?

What is a formula for the parabola in standard form $f(x) = ax^2 + bx + c$? Enter the values of $a, b,$ and $c$ in the appropriate places.
$f(x) =$ $x^2 +$ $x +$

Hint: