Explain the thermodynamic equilbrium constant

When the oxide of generic metal M is heated at 25.0 °C, only a negligible amount of M is produced. O2M (s) <--> M (s) + O2 (g) Delta G = 290 kJ/mol When this reaction is coupled to the conversion of graphite to carbon dioxide, it becomes spontaneous. What is the chemical equation of this coupled process? Show that the reaction is in equilibrium, include physical states, and represent graphite as C(s). What is the thermodynamic equilbrium constant for the coupled reaction?