So this we obtained by assuming that this was at equilibrium. And that's a good assumption because this reaction takes place very quickly. Now, we could basically solve for K minus one divided by K. So we basically take this, we bring it to this side, take this, bring it to this side, and we get this proportion. So K minus one divided by K is equal to the product of these two concentrations divided by the enzyme substrate concentration. And this, from general chemistry, we define to be the equilibrium constant of the dissociation of the enzyme substrate complex. And because Km is equal to K minus one divided by K, which is the same thing as here, the equilibrium constant is equal to Km.