[tex]x^2+67+y^2=8y+20x[/tex]
Let's rewrite the expression as:
[tex]\begin{gathered} x^2+67+y^2-8y-20x=0 \\ so\colon \\ (x-10)^2+(y-4)^2-49=0 \\ (x-10)^2+(y-4)^2=49 \end{gathered}[/tex]
Which is the standard equation of a circle:
[tex](x-h)^2+(y-k)^2=r^2[/tex]
Where (h,k) is the coordinates of center of the circle and r is the radius
Therefore, the center is:
[tex]\begin{gathered} (h,k)=(10,4) \\ \end{gathered}[/tex]
And the radius is:
[tex]r=\sqrt[]{49}=7[/tex]
