Explain why a real gas behaves more like an ideal gas at high temperature and low pressure.

At high temperature the molecules have a large average kinetic energy, so the kinetic energy is much greater than the potential energy of intermolecular attractions.
At low pressure the average distance between molecules is large, so the molecules are far apart and the intermolecular forces become negligible.
Because the kinetic energy dominates, the motion of the molecules is essentially the same as for an ideal gas, where only elastic collisions are considered.
Thus a real gas behaves more like an ideal gas when the temperature is high and the pressure is low.