Circle Equation Radius & Completing the Square

The equation below defines a circle in the xy-plane. What is the radius of the circle?

x^2 + 10x + y^2 - 6y = 47

Desmos 10-Second Shortcut

Desmos 5-Second Shortcut: Type x^2 + 10x + y^2 - 6y = 47 directly into Desmos. Click the center (-5, 3) and top point (-5, 12). Distance = 12 - 3 = 9. Done without paper calculation!

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