Drag the tiles to the boxes to form correct pairs. Not all tiles will be used. Match the pairs of equations that represent concentric circles.
3x2 + 3y2 + 12x − 6y − 21 = 0
5x2 + 5y2 − 10x + 40y − 75 = 0
5x2 + 5y2 − 30x + 20y − 10 = 0
4x2 + 4y2 + 16x − 8y − 308 = 0
x2 + y2 − 12x − 8y − 100 = 0
2x2 + 2y2 − 8x + 12y − 40 = 0
4x2 + 4y2 − 16x + 24y − 28 = 0
3x2 + 3y2 − 18x + 12y − 81 = 0
x2 + y2 − 2x + 8y − 13 = 0
x2 + y2 + 24x + 30y + 17 = 0