the answer to letter A is (x-y)² because if x=5 and y= -3 the problem would be (5-(-3))² and when you have -- that means you add. ik weird right. So basically that would be 8² which equals 64. Rather then the other one which was (x+y)² because again that would be (5+(-3))² but different because of the addition sign. so, that's asking what 5-3 is which is 2² which equals 4. Making (x-y)² bigger. I hope this helped