<Dd> V ∝ 1 P (\ displaystyle V \ propto (\ frac (1) (P))), meaning "Volume is directly proportional to 1 divided by Pressure", or </Dd> <Dd> P ∝ 1 V (\ displaystyle P \ propto (\ frac (1) (V))), meaning "Pressure is directly proportional to 1 divided by Volume", or </Dd> <Dd> P V = k 1 (\ displaystyle PV = k_ (1)), or </Dd> <Dd> P 1 V 1 = P 2 V 2 (\ displaystyle P_ (1) V_ (1) = P_ (2) V_ (2) \,) </Dd>

If the temperature remains constant v and p