7.) the equation of the circle is (x - 3)^2 + (y - 4)^2 = 25
If you substitute the point in you get (6-3)^2 + (8-4)^2 = 25 3^2 + 4^2 = 25 9 + 16 = 25 25 = 25
Both sides of the equation are the same so it proves it lies on the circle
8.) you add the x coordinates together and divide by 2 7 + 4 = 11 11/2 = 5.5 You use +7 because you need to find the midpoint. You then add 5.5 to - 7 or - 5.5 from 4 -7 + 5.5 = - 1.5
You do the same for y coordinates 6+5 = 11 11/2 = 5.5 6-5.5 = 0.5
So the coordinates of Rachel's house are (-1.5, 0.5)