Answer:

Let the usual speed of the train is x km/h.

D=300 km (Given)

Speed=TimeDistance

Time=x300

After increasing the speed of the train ;

New speed is (x+5) km/h

Time=x+5300

Now, difference between the time taken by usual speed and after increasing speed of the train is two hours. Therefore,

x300−x+5300=2

⇒300(x1−x+51)=2

⇒(x2+5xx+5−x)=3002

⇒x2+5x5=1501

⇒x2+5x−750=0

⇒x2+30x−25x−750=0

⇒x(x+30)−

Step-by-step explanation:

Please mark me as brainliest

Answer:

Let the speed of express train be x km/h Then the speed of ordinary train will be (x-12) km/h.

Time taken by express train =

240

x

Time taken by ordinary trian=

240

x

−

12

According to the given condition:

240

x

−

12

−

240

x

=

1

⇒

240

(

x

−

(

x

−

12

)

x

(

x

−

12

)

)

=

1

⇒

240

×

x

−

x

+

12

x

(

x

−

12

)

=

1

⇒

240

×

12

x

(

x

−

12

)

=

1

⇒

2880

=

x

2

−

12

x

⇒

x

2

−

12

x

−

2880

=

0

⇒

x

2

−

60

x

+

48

x

−

2880

=

0

⇒

x

(

x

−

60

)

+

48

(

x

−

60

)

=

0

⇒

(

x

−

60

)

(

x

+

48

)

=

0

∴

x

=

60

,

−

48

Since, speed can't be a negative quantity.

So, the speed of the express train is 60 km/h.