Avogadro's law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. Boyle's law states that the pressure and volume of a gas are inversely proportional when the temperature is constant.
When combining Avogadro's law with Boyle's law, we are looking at the relationship between volume and the number of molecules of a gas when pressure is constant. This can be represented by the following proportionality:
\[ V \propto n \]
In this proportionality, V represents volume, and n represents the number of molecules of the gas. This means that as the number of molecules of the gas increases, the volume will also increase proportionally, given that the pressure remains constant.