How to determine enthalpy change

[HiMyNameIs]

The following reaction is used to convert methane gas into hydrogen which can in
turn be cleanly burned in fuel cells:

CH4(g) + H2O(g) → CO(g) + 3 H2(g) ΔHro

(a) Use the following information to determine the enthalpy change ΔHro associated
with the reaction shown above:

CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) ΔHco (CH4, g) = -890 kJ mol-1

CO(g) + ½ O2(g) → CO2(g) ΔHco (CO, g) = -283 kJ mol-1

H2(g) + ½ O2(g) → H2O(l) ΔHco (H2, g) = -286 kJ mol-1

ΔHvapo (H2O, l) = 44.01 kJ mol-1

[factor-fiction]

Have you attended the lectures or read your text books?
http://www.saskschool...3/lesson3/lesson3.htm
http://www.webchem.ne...ement_of_enthalpy.htm