A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have taken 3 hours more to cover the same distance. We need to find the speed of the train.
2x2 + x – 6 = 0
Here, a = 2, b = 1, c = –6
ac = –12 = 4 x (–3)
b = 1= 4 – 3
∴ 2x2 + x – 6 = 0
⇒ 2x2 + 4x – 3x – 6 = 0
⇒ 2x(x + 2) – 3(x + 2) = 0
⇒ (x + 2) (2x – 3) = 0
⇒ x + 2 = 0 or 2x - 3 = 0
⇒ x = –2 or x = 3/2
Hence, the roots of the given quadratic equation are (-2) and 3/2.