Question 481180
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Hi
Standard Form of an Equation of a Circle is {{{(x-h)^2 + (y-k)^2 = r^2}}}
where Pt(h,k) is the center and r is the radius.
x^2+y^2-6x-8y=0   |completing the Squares
(x-3)^2 + (y-4)^2 = 9+16
{{{(x-3)^2 + (y-4)^2 = 25}}}
{{{drawing(300,300,   -10,10,-10,10,  grid(1),
circle(3, 4,0.4),
circle(3, 4,5),
graph( 300, 300, -10,10,-10,10))}}}