Answer
$f'(x) = 5 $
Work Step by Step
$f(x) = 5x - 4$
$f'(x) = \lim\limits_{h \to 0} \frac{f(x+h) - f(x)}{h}$
$f'(x) = \lim\limits_{h \to 0} \frac{5(x+h) - 4 - (5x-4)}{h}$
$f'(x) = \lim\limits_{h \to 0} \frac{5x + 5h - 4 - 5x + 4}{h}$
$f'(x) = \lim\limits_{h \to 0} \frac{5h}{h}$
$f'(x) = 5 $
