### Home > CCA2 > Chapter 8 > Lesson 8.1.3 > Problem8-59

8-59.

Find the center and radius of each circle below.

1. $(y - 7)^2 = 25 - (x - 3)^2$

Add $(x - 3)^2$ to both sides of the equation.

Center: $(3, 7)$Radius: $5$

1. $x^2 + y^2 + 10y = -9$

Complete the square.

$x^2 + (y^2 +10y + 25) = -9 + 25$

Center: $(0, -5)$ Radius: $4$

1. $x^2 + y^2 + 18x - 8y + 47 = 0$

See parts (a) and (b).

1. $y^2 + (x - 3)^2 = 1$

See parts (a) and (b).