1. x^2 + y^2 - 4x + 12y - 20 = 0 ---- (x-2)^2 + (y+6)^2 = 60
3. 3x^2+ 3y^2 + 12x +18y - 15 = 0 --- (x+2)^2 + (y+3)^2 = 18
5. 2x^2 + 2y^2 - 24x - 16y - 8 = 0 --- (x-6)^2 + (y-4)^2 = 56
I don't know the other two, hope I helped though.
