posted by ladybug .
Write the equation of the circle in standard form. Find the center, radius and intercepts.
x^2 + y^2 + 4x + 2y - 20 = 0
complete the square
x^2 + 4x + 4 + y^2 + 2y + 1 = 20 + 4 + 1
(x+2)^2 + (y+1)^2 = 25
I will let you handle the rest, since this is a very basic result.