What is the standard molar enthalpy of formation for aluminu…

What is the standard molar enthalpy of formation for aluminum oxide (Al2O3) based on the thermochemical equations provided?4Fe(s) + 3O2(g) 2Fe2O3(s)                         ΔH°1 = –1648.4 kJ·mol–12Al(s) + Fe2O3(s)2Fe(s) + Al2O3(s)         ΔH°2 = –851.5 kJ·mol–1   Data sheet and Periodic Table