To find out how big of a TV Don can mount on his wall and still have at least 24 1/2 inches left on both sides, we just need to subtract the amount of space Don wants to save from the amount that Don has total.
Also, decimals are much easier to work with in these types of problems than fractions, so we will convert the fractions to decimals.
88 3/4 = 88.75
24 1/2 = 24.5
Since Don wants to save 24.5 inches on both sides, we will need to multiply 24.5 by 2 before continuing.
24.5 * 2 = 49
Then, we just need to subtract the amount of length he wants to save by the total amount he has.
88.75 - 49 = 39.75
39.75 in fraction form would be 39 3/4
The largest TV Don can fit on his wall while saving the amount he wants to save on both sides for his speakers is 39 3/4 inches. That means he can get either Television A, B, or C.
Hope that helped =)