The answer is 351/22
Steps:
1. You turn the mixed numbers into improper fractions, your new numbers are 211/11 and 71/22
2. Since your least common multiple would be 22 you do 11 times 2 and 211 times 2. Now 211/11 becomes 422/22
3. You do 422/22 minus 71/22
4. Your answer is 351/22