The equations that describe the given circles are:
x^2 + y^2 = 4
x^2 + y^2 = 64
For a circle of radius R, centered at the point (a, b), the equation is:
(x - a)^2 + (y - b)^2 = R^2
In this case, we have two circles, both centered on (0, 0), but one has a radius of 2 units and the other a radius of 8 units, then we have two equations:
x^2 + y^2 = 2^2 = 4
x^2 + y^2 = 8^2 = 64
These are the two equations that describe the given circles.
If you want to learn more about circles, you can read:
https://brainly.com/question/25306774