Tutorial Exercise Write the equation of the circle in standard form. 2x2 + 2y2 2x 2y 71 = 0 Identify its center and radius. Step 1 The equation of a circle with center at (h, k) and radius r is given by the following. x 2 + y 2 = r2. To bring the equation 2x2 + 2y2 2x 2y 71 = 0 into the above form, first add 71 to each side of the equation and then divide each side by 2. 2x2 + 2y2 2x 2y 71 + 71 = 0 + 71 2x2 + 2y2 2x 2y = 71 x2 + y2 x y =