Please explain how I can simplify this: (1/x) / (1/x)^2 + 1 to get this answer x/ x^2 + 1

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.