recall,
Circle centered at (h,k) and radius r --
[tex](x-h)^2+(y-k)^2=r^2[/tex]
Here it is a circle centered at (h,k)=(5,6) and radius r=6
If you move to the right, the x coordinate will increase, so here the only change is the x coordinate increases by 2.
[tex](x-5)^2+(y-6)^2=r^2[/tex]
[tex](x-7)^2+(y-6)^2=6^2[/tex]