Answer with explanation/solution.

51. What is the equation of a unit circle? a. x + yz = 1 b. x3 - yz = 1 c. x + y=0 d. X- y=0 52. Which of the following equation describe a circle on the coordinates plane with radius of 4 units? A a. (x - 4)2 + (y - 4)2= 22 c. (x + 2)2 + (y + 2)?= 42 b. (x - 2)2 + (y - 2)2 = 42 d. (x - 4)+ (y -4)= 162 53. Which equation describes a circle with a center at (2, -3) and radius of 5 units? a. (x - 2) + (y + 3)2= 252 c. (x - 3)2 + (y -2)? = 253 b. (x + 2)2 + (y-3)2= 52 d. (x - 2)2 + (y + 3)2 = 57 54. What is the center and radius of a circle whose equation is x + y? + 10x - 6y - 2 = 07 a. C(-5, 3); 1 = 6 b. C(-3, 5): r =6 c. C( 5, -3):1=6 d. C( -3, -5); 1 = 6 55. The endpoints of a diameter of a circle are L(-3, -2) and G(9, -6), what isa the length of the radius of the circle? a. V10 units b. 2V10 units c. 4v10 units d. 8v10 units