Identify the following reactions as combination, decomposition, or combustion reactions
 C7H8 + 9O2 → 7CO2 + 4H2O ______________
 2NaHCO3 → Na2CO3 + H2O + CO2 ___________
 CH4 → C + 2H2O ________________
 P4O10 + 6H2O → 4H3PO4 ______________
 FeSO4 → FeO + SO3 _______________
 CaCO3(s) → CO2(g) + CaO(s) _________________