Can somebody please help me with this review

is is corecct nice job kid

Step-by-step explanation:

it would be a function because every input has exactly one output.

The center-radius form of the circle equation is in the format (x – h)^2 + (y – k)^2 = r^2, with the center being at the point (h, k) and the radius being "r". We do as follows:
x^2 − 4x + y^2 + 8y = −4(x^2 − 4x) + (y^2 + 8y) = −4(x^2 − 4x + 4) + (y^2 + 8y + 16) = −4 +4 + 16(x - 2)^2 + ( y + 4)^2 = 16 = 4^2
Center: (-2 , 4 )radius: 4