∵ (–5) is a root of the quadratic equation
∴ 2x2 + px – 15 = 0
2(–5)2 + p. (–5) – 15 = 0
⇒ 50 – 5p – 15 = 0
⇒ –5p + 35= 0
⇒ –5p = –35
⇒ P = 7
Now. the quadratic equation 7(x2Â + x) + k = 0
i.e. 7x2Â + 7x + k = 0 has equal roots.
∴    Its discriminant Â
      Â
       Â
Hence, Â Â