Posted by Eli on .
If you need 138 balloons and have 5 bags, each bag has same number of balloons in it. We need 18 more balloons to finish How many balloons in each bag?

math 
Quidditch,
Let B = the number of balloons in each bag. The problem says that each bag has the same number of balloons. Also, after all the bags are used, 18 more balloons are still needed to get to 138.
The equation would be:
5B + 18 = 138
To solve for B first subtract 18 from each side:
5B = 120
The last step is to divide both sides by 5 to get a single B on the left and the number of balloons in a single bag on the right.