17. Complete the square for the circle a' - 4r = -y' + 10y - 20 to write the circle in standard form: (x - h )' + (y-k)= = The center of the circle is: A. (-2. -5) B. (-2.5) C. (2, -5) D. (2,5) E. (4, 10) 18. The radius of the circle in question 17 is: A. 1 B. V5 C. 3 D. 5 E. 9 19. The area of the following triangle is: B 450 0 = 12 70 A. 49.1 B. 52.8 C. 86.7 D. 98.2 E. 105.6 20. Completing the square for 2x? + 8x + 1 gives 2(2 + 2)' + c. c= A. -5 B. C. -9 D. -7 E. 7