L.H.S. = (2x – 1) (x – 3)
= 2x2 – 6x– + 3
= 2x2 – 7x + 3
R.H.S. = (x + 5) (a – 1)
= x2 + 5x – x – 5
= x2 + 4x – 5
∴2x2 – 7x + 3 = x2 + 4x – 5
⇒ 2x2 –x2-7x–4x+ 3 + 5 = 0
⇒ x2 – 11x + 8 = 0
∵ It is of the form ax2 + bx + c = 0 where a = 1, b = –11, c = 8.
Hence, the given equation is a quadratic equation.