here is a problem :
What I did " as shown in the picture below "
I rewrote the information given in terms of reactants and products ( equations )// in Part 1
Then I used the Hess law to obtain the desired result //in part 2
in part 3 // I added and cancelled the terms that appear in both sides
but I left with $O_{(g)}$ !! and the enthalpy is 1192 which is inconsistent with the correct value 1442 !!
What's wrong?