Answer
$\frac{ln(16)}{5}$
Work Step by Step
$\int_{0}^{3}\frac{dx}{5x+1}$
Let $u = 5x+1$
$\frac{du}{dx} = 5$
$dx = \frac{du}{5}$
When $x = 0$, then $u = 1$
When $x = 3$, then $u = 16$
$\int_{1}^{16}\frac{1}{5}\cdot \frac{du}{u}$
$= \frac{1}{5}~[~ln(u)\vert_{1}^{16}~]$
$= \frac{1}{5}~[~ln(16) -ln(1)~]$
$= \frac{1}{5}~[~ln(16) -0]$
$= \frac{ln(16)}{5}$