Let's write the rate law for our second step to slow step. So rate is equal to k two or some constant for going this way times the concentration of Nobr two times the concentration of no. Now, notice that this guy appears here and here. Therefore, we can represent this guy in terms of all these guys. So let's bring the k negative one over and we get the following. Nobr or the concentration of Nobr equals k one divided by k minus one, right times no or concentration of no times the concentration of BR two.