Find the equation of the circle whose radius is `5` and which touches the circle `x^2+y^2-2x-4y-20=0` externally at the point `(5,5)`.

Explanation

To find the equation of the circle with a radius of 5 that touches the given circle externally at the point (5, 5), we can follow these steps:

### Step 1: Find the center and radius of the given circle
The equation of the given circle is:
\[ x^2 + y^2 - 2x - 4y - 20 = 0 \]
We can rewrite this in the standard form \( (x - h)^2 + (y - k)^2 = r^2 \).
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