Answer:
896.5
Explanation:
You want to manipulate each equation individually.
First Equation: Keep it how it is, because N2 is the same in the final and 1st equation
Second Equation: Multiply the enthalpy by 4 because you want the H2Os to be equal
Third Equation: Switch the sign of the enthalpy because you want toe H2O2 on the other side of the equation, and multiply by 2 to match the coefficient
