Shrinking the Gap Algebraically

For the curve

$f(x) = 2x^2 - 5x$

you want the instantaneous rate of change at $x = 3$. Instead of building a table of shrinking gaps, do it once with algebra: form the average rate of change from $x = 3$ across to $x = 3 + h$,

$\frac{f(3+h) - f(3)}{h}$

simplify it as far as it will go, and then say what number those averages settle on as $h$ shrinks toward $0$.

Which pair is correct?