please answer this my topic is all about sums and differences of rational algebraic expression 3/5 + 4/5 another is x/3 - y/3 another is 7/a + 2/a please answer it thanks!!!!!

3/5 + 4/5 = 7/5

x/3 - y/3 = (x-y)/3

See if you can do the third one from seeing the two above.