math 20
posted by Jenna on .
Using the procedure of comlpeting the square, write the equation x^2+y^26x+8y=0 in the form (xh)^2+(yk)^2=r^2.
state the domain and range
where(h,k) is the center of the circle and r is the radius

first,
(x^26x + ?)+(y^2+8y+?)=?
we need (3)^3 in the x, and 4^2 in the y
(x^26x+9)+(y^2+8y+16)=9+16
(x3)^2 + (y+4)^2=5^2 
how did u get 3^3 and 4^2?