\[\begin {array} {1 1} (1)\;\bigg(8,\frac{15}{2}\bigg) & \quad (2)\;\bigg(-8, \frac{15}{2}\bigg) \\ (3)\;\bigg(8,\frac{-15}{2}\bigg) & \quad (4)\;\bigg(-8,\frac{-15}{2}\bigg) \end {array}\]