Question

the correct answer is (d) 235 kj, I just don't know why, could provide a step by step explanation of how to get the answer?

Find the AH for the reaction below, given the following reactions and subsequent AH values: 2CO2(g) + H20(g) → C2H2(g) + 5/201g) C2H2(g) + 2H2(g) → C2H6(g) H2O(g) -> H2(g) + 1/2O2(g) 14. ΔH =-94.5 kl H =71.2 kJ Crk(g) + 7/202(g) → 2CO2(g) + 3H2O(g) AH-283 kl a. +283 kJ b. +94.5 k d. 235 k e. -142.4 k