Problem

Find the solution of the differential equation

$$\begin{align*} \frac{\mathrm{d}y}{\mathrm{d}x} -&\, \frac{2x + 6}{x^2 + 6x + 5}y =&\, 4, \end{align*}$$

given that $y = 0$ when $x = 0$. Give your answer in an exact form.