The equation of a cirecle with radius r and center at (h,k) is (x-h)^2+(y-k)^2=r^2 r=10 center=(-2,-4) (x+2)^2+(y+4)^2=10^2 (x+2)^2+(y+4)^2=100 (x,y) sub given points (or use TI) and see if you get a true statmeent A is on it
The equation of of circle = (x+2)^2 + (x+4)^2 = 100 by sub. by this points in the circle equation for point V(8,-4) (8+2)^2 + (-4+4)^2 = 100 so the point V lay on the circle