A gas expands in a piston cylinder device from to , the process being described by , where is in , i — Thermodynamics and Thermochemistry Chemistry Question

Question

A gas expands in a piston cylinder device from $V_1$ to $V_2$, the process being described by $PV = a + bV$, where $P$ is in $\text{Nm}^{-2}$, $V$ is in $\text{m}^3$ and $a$ and $b$ are constants. The work done in the process is