In other words, if it's greater than one, that means our equilibrium lies to the right. Because these guys completely react to form our products. In other words, if K is much larger than one, we have very little of our concentration of A and a lot of concentration of products, namely C and D.
Likewise, if K is much less than one, that means we have lots of this guy left over at equilibrium and very little affirmation of our products. And that means equilibrium lies to the left, which also means we have very little of this guy and a lot of this guy. Now, let's look at B. So we just learned that the change in Gibbs free energy is equal to negative.