SOLUTION: Hi 2 cars travel 300km .car A finished 3 hours earlier than car B .if car A averaged 5kmph more than car B what was car B average speed. Thanks

The time equation is


     -  = 3


Cancel factor 3 in both sides


     -  = 1.


Multiply both sides by x*(x+5).

Reduce to the standatd form quadraric equation.

Solve the quadratic equation by any way you want / you know / you like.


ANSWER.  Car B: 20 kph.  Car A: 25 kph.

Let B's speed be S

Then A's speed = S + 5

We then get the following TIME equation: 

 ----- Reducing fractions by factoring out numerator-GCF, 3

100(S + 5) = 100S + S(S + 5) ----- Multiplying by LCD, S(S + 5)



0 = (S - 20)(S + 25)

0 = S - 20          OR            0 = S + 25

B's speed, or          OR        S = - 25 (ignore)