Gibbs energy graph

[nshahwan 1L]

Could someone explain the Gibbs free-energy curve shown in figure 5I.3 in the book. The book explains it but I don't quite have a grasp of it.

[Skyllar Kuppinger 1F]

graph a is showing an exothermic reaction. The Gibbs free energy starts high and ends low, meaning the net change in free energy is negative. we know that if delta G is negative, then the rxn is exothermic. this also means that the reaction lies to the right, so K > 1. Graph b is showing an endothermic rxn, where the net change in Gibbs free energy is positive. this also means that the reaction lies to the left, so K<1.