46) Center: \( (-2,7) \) Radius: 9

Step 1 ：Write the equation of a circle: \((x-a)^2 + (y-b)^2 = r^2\)

Step 2 ：Substitute the center coordinates \((-2,7)\) and radius 9: \((x-(-2))^2 + (y-7)^2 = 9^2\)

Step 3 ：Simplify the equation: \((x+2)^2 + (y-7)^2 = 81\)