8 − 3m + 2m − 8m = 6m − 4m + m + 20

3 × 5 − 7 + 14 ÷ 7 = 10

6y + 3 = 21

1/2x × 3 = 12

Mrs. Hendrickson bought her friend a cup of coffee that cost $3. She also bought her friend an ice cream cone that cost $2.20. She paid for all of it with a $15 bill. What was her change?