Question

Need help. Please!

Answer 1

I was thinking it's C.

Answer 2

We have given center (h , k) that is (2 , -1)
WE know that equation of circle = (x - h)^2 +(y - k)^2= r^2
So find radius r by distance formula we have given two points ( x1, y1) & (x2,y2)
Therefore r^2 = (x2 - x1)^2 + (y2 - y1)^2 = (2 - 2)^2 + (3 - (-1))^2 = 16
Therefore we have got ( x - 2)^2 + (x +1)^2 = 16