Math
posted by Molly on .
Mike drove to a friends house at a rate of 40 mph he returned by the same route at 45 mph The driving time round trip was 4 hours. write and solve an equation to find the distance Mike traveled

since time = distance/speed,
d/40 + d/45 = 4
d = 84.7 miles
round trip = 169.4 miles
check:
84.7/40 = 2.118
84.7/45 = 1.882
total: 4.000 hours