A train travels 1

Let, the distance covered by the train = d km

Speed of the train = s km/hour

And the time taken by the train = t hour

180 = s × t …(1)

180 = (s + 9) × (t – 1) ⇒ …(2)

From eq.(1) and eq.(2)

180s + 1620 = 189s + s²

s² + 9s – 1620 = 0

(s – 36)(s + 45) = 0

s = 36 and -45

But, speed of train is neither be negative.

So, speed of train is 36 km/hour.

OR

⇒

⇒ 3x – 8 = 2x² – 13x + 15

⇒ 2x² – 16x + 23 = 0

⇒

⇒

⇒

⇒ and

So, the roots of the equation are and