answer and explanation
we know that Boyle's law states that the volume of a gas at a constant temperature varies inversely with pressure exerted on it. mathematically this can be described by:
PV= k
and we know that Charle's law states that the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature, if the Pressure remains constant. mathematically this is
V/T = k
these can be combined to give the combined gas law which basically states that as long as the amount of gas doesn't change, the ratio between Volume-Pressure and Temperature of a system is constant.
mathematically this can be represented as:
k = PV/T