comlete the square to get into form
(x-h)²+(y-k)²=r²
where teh center is (h,k) and radius is r
so
group x's together and y's together
(x²-6x)+(y²+10y)+25=0
take 1/2 of each linear coeifnet and square it
-6/2=-3, (-3)²=9
10/2=5, 5²=25
add that to both sides
(x²-6x)+(y²+10y)+25+9+25=0+9+25
(x²-6x+9)+(y²+10y+25)+25=34
complete the squares
(x-3)²+(y+5)²+25=34
minus 25 both sides
(x-3)²+(y+5)²=9
get into form
(x-3)²+(y-(-5))²=3²
center is (3,-5) and radius is 3
