6x^2 + x - 15 = 6x^2 - 9x + 10x - 15 = 3x(2x - 3) + 5(2x - 3) = (3x + 5)(2x - 3)
Therefore, the other factor is 3x + 5.
So car A travels Distance = 60 km/hr*(1+x)
Car B travels Distance = 75 km/hr(x)
Where x is the time in hours.
Those two equations are equal when on overtakes the other
so:
60 +60x = 75x
60=15x
x=4, but my expression is written to count from when car B commenced travel. So total time is 5 hours from the car A setting off.
Answer:
it is called Common Multiples