Question 358081
The distance formula D = rt can be written as t = D/r when looking for time where D = distance, r = rate or speed and t = time in hours.


We are searching for time.


(total distance for commuter plan)/(x + 90) = (total distance for bus)/x


Now, (x + 90) tells us that the commuter plan is 90 mph faster than the bus' rate represented here by x.


The final equation looks like this:


525/(x + 90) = 210/x


After we cross-multiply, x = 60.


I have not found the answer.  I simply found the value of x.  I need to find the speed of each.


So, x = bus speed or 60 mph.


The commuter plan's speed is 60 + 90 or 150 mph.