For the equation you could do 2n = 24. It basically means that n is the number of sandwiches, and since every sandwich has 2 slices, how many sandwiches would it take to get to 24 slices or how many sandwiches does 24 slices make.
To solve the first equation, 2n = 24, get n by itself by dividing both sides by 2 to get n = 24/2, then simplify 24/2, which is 12. So Deion can make 12 sandwiches with 24 slices of cheese.