We have that the equation of the circle is the following:
[tex](x-h)^2+(y-k)^2=r^2[/tex]
where (h,k) is the center of the circle and r is the radius.
In this case,we have that the center is the point:
[tex](h,k)=(3,0)[/tex]
also, notice that between the center and any point of the circle are 5 units away, therefore, r = 5.
Then, the equation of the circle is the following:
[tex]\begin{gathered} (x-3)^2+(y-0)^2=(5)^2 \\ \Rightarrow(x-3)^2+y^2=25 \end{gathered}[/tex]
