Answer:
The radius is: 
Step-by-step explanation:
The equation of a circle in center-radius form is:

Where the center is at the point (h, k) and the radius is "r".
So, given the equation of the circle:

You can identify that:

Then, solving for "r", you get that the radius of this circle is:

$21 because 3$x$7(numbers of days in a week)is $21. I hope this helps :)
Wait what’s the value of x?
Yes, they certainly do exist.
Do you have a question to ask ?
Is 3 dollar per peso I hope this help you