Answer:
John has 9 baseball cards left.
Step-by-step explanation:
First, you have to find how many baseball cards John has in the begining before he starts giving them away. In the problem, it states that John had 30 baseball cards.
Next, you have to find how how many he gave away. In the problem, it states that he gave 14 to Mike and 7 to Jeff. Instead of subtracting the numbers one by one, we'll make it easier. Add 14 to 7 and you'll get 21.
Then, you subtract 21 from 30, and you'll get 9.
John has 9 basball cards left.
P.S. If you want the equation, the equation is 30-(14+7)=x or 30-21=x
