Describe the given set of points with a single equation or with a pair of equations. The circle of radius 4 centered at the point (7.-1, 1) and lying in a plane perpendicular to the x-axds (y + 1)+(2-1) = 16 and x = 7 (y + 1)+(2-1) = 16 and y + z = 0 O +1=16 0. 16 and x = 7