Final answer:
The gas law represented by the formula P1/T1=P2/T2 is Gay-Lussac's law, which relates the pressure of a gas to its temperature at constant volume (1).
Step-by-step explanation:
The simple gas law that has the form P1/T1=P2/T2 is known as Gay-Lussac's law. This law states that, for a given amount of gas at constant volume, the pressure of the gas is directly proportional to its absolute temperature.
If the temperature increases, the pressure increases as well, and vice versa, as long as the volume doesn't change. Charles's law relates volume to temperature at constant pressure, while Boyle's law relates pressure to volume at constant temperature. Avogadro's law, on the other hand, states that volume is directly proportional to the number of gas moles at constant temperature and pressure.