Answer:
-7/15
Explanation:
To get the sum of two fractions, you need to make their denominators the same, ideally the least common denominator, or LCD.
So, first off, substitute x + y with the values of the variables to get -4/5 + 1/3. Next, find the LCD of the fractions. In this case, the denominators are both prime, so the LCD is the product of the denominators. Because 3 * 5 = 15), both denominators should end up being 15. Next, multiply both parts of both fractions by the number needed to get to that LCD. In this case, you're multiplying -4/5 by 3 on the top and bottom, and 1/3 by 5 on the top and bottom. This should get you an expression of -12/15 + 5/15. Next, add away! (-12 + 5)/15 = -7/15, and you're done!