唔識做第35題,用過２種方法都計唔到...?

Circle 嘅 Equation 係 x² + y² + Ax + By + C = 0
分別代 (0,3), (-5,0), (-3,8) 入 Equation 到
之後搵番 A, B, C

http://s3.postimg.org/u3npx4ooh/image.png