Answer
4
Work Step by Step
We are given:
$f(x)=4x+3$
We find the difference quotient:
$\displaystyle \frac{f(x+h)-f(x)}{h}=$
$\displaystyle =\frac{4(x+h)+3-(4x+3)}{h}$
$\displaystyle =\frac{4x+4h+3-4x-3}{h}$
$\displaystyle =\frac{4h}{h}$
$=4$