Posted by Lisa on .
At 10:30 am two planes leave to Houston, one flying east 560km/h and the other flying west at 640 km/h. At what time will they both ne 2100km apart.

Acc. Algebra 2 
Reiny,
They would be flying for the same amount of time , t hours
distance covered by first = 560t km
distance covered by second = 640t km
560t + 640t = 2100
1200t = 2100
t = 1.75 hrs
or 1 hour and 45 minutes
so at 10:30 + 1:45 or 12:15 pm they will be 2100 km apart