Answer:
17/20 of the pizza.
Explanation:
First, we need to give these two fractions a common denominator, to do this, we need to find the LCM of 4 and 5. The LCM of 4 and 5 is 20. Now, we multiply 1/4 by 5/5 and mulitply 3/5 by 4/4. When we do this, we get 5/20 and 12/20. Now, we add those fractions and simplify (if we can). When we add them (don't add the bottom numbers), we get 17/20. We can't simplify this, so we just leave it as it is. I hope this helped!