The combined gas<span> law states that the </span>pressure of a gas<span> is inversely related to the</span>volume<span> and directly related to the </span>temperature<span>. If </span>temperature<span> is held constant, the equation is </span>reduced<span> to Boyle's law. Therefore, if you </span>decrease<span> the </span>pressure<span> of a fixed amount of </span>gas<span>, its </span>volume<span> will increase.</span>