Question

What is the center and radius of this circumference? 5x²+5y²=20

Answer 1

The equation of a circle with a center of (h,k) with a radius of "r" is
$(x-h)^2 +(y-k)^2=r^2$

looking at the given equation,
5x^2 +5y^2=20
divide 5 to both sides to get
x^2+y^2 =4

now compare that to the equatio of a circle shown above