Match the circle equations in general form with their corresponding equations in standard form. x2 + y2 ? 4x + 12y ? 20 = 0 (x ? 6)2 + (y ? 4)2 = 56 x2 + y2 + 6x ? 8y ? 10 = 0 (x ? 2)2 + (y + 6)2 = 60 3x2 + 3y2 + 12x + 18y ? 15 = 0 (x + 2)2 + (y + 3)2 = 18 5x2 + 5y2 ? 10x + 20y ? 30 = 0 (x + 1)2 + (y ? 6)2 = 46 2x2 + 2y2 ? 24x ? 16y ? 8 = 0 x2 + y2 + 2x ? 12y ? 9 = 0

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.