Question 148286
Find the center and radius of the circle (x-5)2 + y2 + 2y=7
Put in the form {{{(x-a)^2+(y-b)^2 = r^2}}}
x is ok as it is.
Complete the square for y
{{{y^2+2y+1 = (y+1)^2}}}, so add 1 to both sides:
{{{(x-5)^2+(y-(-1))^2 = 8}}}
The center is at (a,b), or (5,-1) and the radius is {{{sqrt(8)}}}.
{{{sqrt(8) = 2sqrt(2)}}}