CBSE Class 10 Answered
As shown below this example is an example of quadratic equation and variables are 3, so can't be solved UNLESS THE SCHEDULED TIME OF THE TRAIN IS GIVEN.
Let U be the uniform speed and T be regular time.
then the distance is D = UT.
If U + 6, then T - 4,
and U - 6, then T + 6,
But the product would still be the same distance, as the distance can't change.
(U+6)(T-4) = (U-6)(T+6)
UT -4U + 6T - 24 = UT + 6U - 6T - 36
10U - 12T - 12 = 0
10U - 12D/U - 12 = 0
10U2 - 12D - 12U = 0