Rewrite in standard form. Find the center and radius of the circle. Show all of your work for full credit

The standard form of a circle is x^2 + y^2 = r^2 for a circle with center at the origin (0, 0). For circles with center at (h, k), the standard form is (x-h) ^2 + (y-k) ^2 = r^2. If given an equation, convert it to standard form by completing the square and then simplify the equation. The radius is determined by isolating the constant term at the left side of the equation and taking its square root.