Question 911750
Being a travel problem with simple rates and distance,
RT=D uniform rates rule for travel, RATE, TIME, DISTANCE.


4 mph uphill and 6 mph downhill.
18 miles in 4 hours.


Some thinking...


Nothing comes into mind easily.  Try making a table of data.


______________rate___________time__________distance
UPHILL________4_______________x
DOWNHILL______6_______________y


Notice the assigning of variables for times.



Use RT=D idea to put in expressions for distances.


______________rate___________time__________distance
UPHILL________4_______________x____________4x
DOWNHILL______6_______________y____________6y



You were given the total time and total distance.


______________rate___________time__________distance
UPHILL________4_______________x____________4x
DOWNHILL______6_______________y____________6y
Totals________________________4____________18


You may be able to now see what next to do.  Tell me if you still have trouble continuing from this data table.