In a paragraph, explain how the single remaining commandment in chapter 10 sums up the attitude of the pigs that enables them to break all seven...

This is a great request. Let's start with the wording of that one commandment in chapter ten. 

ALL ANIMALS ARE EQUAL BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS

This commandment is the diametric opposite of what is stated in the beginning of the book. "No animal must ever kill any other animal. All animals are equal." In fact, the last commandment is of Animalism: "All animals are equal." 

When Napoleon added the words,"more equal," he did two things.  First, he still had the idea of equality.  The less educated of the animals might still believe that there is equality.  Hence, the semblance of equality is present.  Second, by stating that some animals are more equal than others, Napoleon is able to do whatever he wants.  The simple reason for this is based on the fact that he and the other pigs are more equal than others.  They are a special class.  Therefore, they can dress the way the want, do what they want, interact with whom they want, and rule themselves.  This makes null all the commandments.