7r+10=3r+50

show the work with the answer. also, if you could do the check, that would be very . you s much : ))

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.