English Language and Literature homework help

From the following enthalpy changes, C (s) + ½ O2 (g) ? CO (g) ?H° = -110.5 kJ CO (g) + ½ O2 (g) ? CO2 (g) ?H° = -283.0 kJ calculate the value of ?H° for the reaction C(s) + O2 (g) ? CO2 (g).