Chemistry Q?

Question

Given the data
(1) N2 (g) + O2 (g) to 2NO (g) delta H = +180.7kJ
(2) 2NO (g) + O2 (g) to 2NO2 (g) delta H = -113.1kJ
(3) 2N2O (g) to 2N2 (g) + O2 (g) delta H = -163.2kJ
use Hess Law to calculate delta H for the reaction: N2O (g) + NO2 (g) to 3NO (g)

Answer 1

Half (3) - half (2) + (1)

Multiply the equations and the enthalpy changes as I have indicated.