Write the equation of the circle in standard form. Find the center, radius and intercepts.

Question

x^2 + y^2 + 4x + 2y - 20 = 0

Answer 1

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.