How would a change in pressure affect a gaseous system in equalibrium?

A change in pressure in a gaseous system at equilibrium will shift the equilibrium position according to Le Chatelier's principle. If the pressure is increased, the system will favor the direction that produces fewer moles of gas to reduce the pressure. Conversely, if the pressure is decreased, the equilibrium will shift towards the side with more moles of gas to increase pressure. This response helps the system counteract the change in pressure and re-establish equilibrium.