(a) For adiabatic change equation of state is
$pV^{\gamma} = constant$
It can also be re-written as
$TV^{\gamma - 1} = constant\ \left\lbrack as\ p = \frac{nRT}{V} \right\rbrack$
and $p^{1 - \gamma}T^{\gamma} = constant\left\lbrack as\ V = \frac{nRT}{P} \right\rbrack$