Question 1119145
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<pre>
Perform completing the squares for x and y separately to transform the given equation to the standard equation of the circle:


x^2 + y^2 + 8x - 10y = -5


(x^2 + 8x) + (y^2 - 10y) = -5                        <<<---=== first step - grouping


(x^2 + 8x + 16) + (y^2 - 10y + 25) = -5 + 16 + 25    <<<---=== identical transformations


{{{(x+4)^2}}} + {{{(y-5)^2}}} = 36.                                 <<<---=== complete the squares


You got the standard equation of the circle.


<U>Answer</U>.  The radius of the circle is  {{{sqrt(36)}}} = 6.
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Solved.