Consider a circle whose equation is x2 + y2 + 4x - 6y - 36 = 0. Which statements are true? Check all that apply.
 To begin converting the equation to standard form, subtract 36 from both sides.
 To complete the square for the x terms, add 4 to both sides.
 The center of the circle is at (-2, 3).
 The center of the circle is at (4, 6).
 The radius of the circle is 6 units.
 The radius of the circle is 49 units.