Completing the Square for a Circle Equation

[Guest]

Hey, I was wondering if someone could check this problem, I think I did it right but am not 100% confident.

The problem is:
x^2 + y^2 - 5x - 6y + 4 = 0

My Work:

x^2 - 5x + 25/4 + y2 - 6y +9 = -4 + 25/4 + 9
(x - 5/2)^2 + (y - 3)^2 = (the square root of) 25/ (the square root of) 4

My Answer:
C(5/2, 3); r=5/2

does this look right?

thanks so much!!

 

[Guest]

actually i meant for the radius to say 5/5

 

[Unco]

The problem is:
x^2 + y^2 - 5x - 6y + 4 = 0

My Work:

x^2 - 5x + 25/4 + y2 - 6y +9 = -4 + 25/4 + 9
(x - 5/2)^2 + (y - 3)^2 = (the square root of) 25/ (the square root of) 4
The left-hand side is perfect. As for the right-hand side: -4 + 25/4 + 9 = ?

The radius will be the square root of that.