A 555-mile, 5-hour plane trip was flown at two speeds. For the first part of the trip, the average speed was 105 mph. Then the tailwind picked up, and the remainder of the trip was flown at an average speed of 115 mph. For how long did the plane fly at each speed?
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555 – d = 115(5 – t)
555 = 105t + 115(5 – t)
555 = 105t + 575 – 115t
555 = 575 – 10t
–20 = –10t
2 = t
2 hours, 3 hours.
555 = 105t + 115(5 – t)
555 = 105t + 575 – 115t
555 = 575 – 10t
–20 = –10t
2 = t
2 hours, 3 hours.