Matthew bought flowers for his mom. he bought 12 flowers that were a combination of roses and lilies. the roses cost $1.75 each and the lilies cost $2.00 each. he spent $21.75. how many of each flower did he buy?

To solve this problem you must apply the proccedure shown below:

1. Let's call: the number of roses and the number of lilies.

2. You must make a system of equation based on the information given in the problem above:

3. Use the method of substitution. First, solve for in the second equation, then substitute it into the first equation, and then solve for :

4. Now, substitute into the second equation:

Therefore, the answer is: roses and lilies.