Answer: 54/4 or 13 2/4
Step-by-step explanation: So first you have to make both fractions into improper fractions. So 15(4)+3=63 over the denominator which is 4. And 2(4)+1=9 over the denominator which is 4. Then subtract the two fractions: 63/4-9/4, and since the two denominators are the same you keep it as 4. So the answer would be 54/4 or if you need it to be a mixed number, 13 2/4.