You are adding up the quarters and dimes from your piggy bank so you can buy a new book. you have a total of 50 coins that add up to $9.80. how many quarters and how many dimes do you have?

Let be the number of quarters you have, and be the number of dimes you have. With the information provided above, you have the following equation:



Next, you know the value of a quarter is 0.25, and the value of a dime is 0.10, so you can set up the next equation:



Substituting the first equation into the second leads to the following:



Solving for will give you the number of dimes you have, and then you can easily figure out how many quarters you have as well.

The answer would be $68.04