This is the next part to the Kinetics 5, Kinetics 6, and Kinetics 7.

add both the reactions to get the overall reaction and cancel out the species which are present on both the sides.

Remember ..an intermediate is the one which is produced in one of the step and then used up in the next step.Now you have to check which species is produced in step one and used up in step 2
Slowest step is going to determine the rate law of the reaction.
Rate =k[H2][NO]^2