Answer:

Step-by-step explanation:
Required
The equation of the circle
The equation of a circle is:

Where:


From the graph, we have


So:
becomes


5 brownies and 15 cookies.
Working
4 plates —> 2B + 6C
1 plate —> 2/4B + 6/4C
10 plates —> 5B + 15C
The answer is a have a great day/night !