Question

If the equation of a circle is (x + 5)2 + (y - 7)2 = 36, its radius is
6
16
36

Answer 1

i think its 6

Answer 2

in general
circle's equation is (x-a)^2+y-b)^2=r^2
r be the raduis and (a,b) be the center
so try to write 36 as square

Answer 3

yes it is :)

Answer 4

open bracket and compare ax2+by2+2gx+2fy+c=0
radius=sqrt(g*g+f*f-c)

Answer 5

no need just rewrite 36 as 6^2
and 6 be the radius that's all