Question

The equation for a circle is ​x2−8x+y2−2y−8=0​ .

Answer 1

Answer:(x−4)2+(y−1)2=25 is the answer

Answer 2

You can analyze it in this way:

1)(2) in y2-2y can show that was (y-1)^2 so we add -1 to -8 => -9

2)(8) in x2-8x show us that was (x-4)^2 so we add -16 to -9 => -25

and finally we have:(x-4)^2 + (y-1)^2 =25

it means C is true!