Question

Find the center and radius of the circle x2 - 22x + y2 + 20y =4

Answer 1

x² - 22x + y² + 20y = 4

x² - 22x + 121 + y² + 20y + 100 = 225

(x - 11)² + (y + 10)² = 15²

Center: (11, -10)

Radius: 15