Final answer:
The equation P1 x V1 = P2 x V2 represents Boyle's Law, which is derived from the combined gas law by keeping temperature constant.
Step-by-step explanation:
The equation P1 x V1 = P2 x V2 is an expression of Boyle's Law. This law applies when the temperature and the amount of gas remain constant. It states that the pressure of a given mass of an ideal gas is inversely proportional to its volume, implying that if volume increases, pressure decreases and vice-versa, provided temperature and amount of gas do not change.
From the combined gas law, when we hold the temperature constant, the formula simplifies to Boyle's Law. It's important to understand that other gas laws, such as Charles's Law and Gay-Lussac's Law, can also be derived from the combined gas law by holding different variables constant. Charles's Law relates the volume and temperature of a gas at constant pressure, whereas Gay-Lussac's Law relates the pressure and temperature at constant volume.