Acircle has the equation x^2−8y−6x+y^2=4.

a: what value should be added to each side of the equation to complete the square for the x's?

b: what value should be added to each side of the equation to complete the square for the y's?

c: what is the standard form of the equation?

select three answer choices: one for question a, one for question b, and one for question c.

a: 3
b: 4
c: (x−3)2+(y−4)2=29
a: 36
b: 16
c: (x−3)2+(y−4)2=16
a: 9
c: (x−3)2+(y−4)2=25
b: 64