Hey there!
You have to find a common denominator. That is 15. So multiply 4/5 by 3 on the bottom and top to get 12/15. Multiply 1/3 by 5 to get 5/15. The equation is now 12/15-5/15. 12-5=7. You don’t change the denominator though, so the answer would be 7/15.
I hope this helps!
