Remember, in this case, because of what we did in equation six, this is simply this here. This does not change, but we want to change e and replace it with something that contains Es. And so we take equation seven, we rearrange equation seven and solve for this. We get that the concentration of the enzyme that is not bound to anything is equal to the total enzyme concentration minus the enzyme concentration that is bound to our substrate. And now we take equation five and replace this quantity with this here. And so we get the following result.