A plane travels 1200 miles against the jet stream, causing its airspeed to be decreased by 20 miles per hour. On the return flight, the plane travels with the jet stream so that its airspeed is increased by 20 miles per hour. If the total flight time of the round trip is 6 and 1/3 hours, what would be the plane's rate in still air?
1200/r-20 + 1200/r+20=19/3
LCM is 3(r-20)(r+20); so
3*1200(r+20) + 3*1200(r-20)=19(r-20)(r+20)
3600r+7200+3600r-7200=19(r[squared]-400)
7200r=?
I am stuck at this point.
1200/r-20 + 1200/r+20=19/3
LCM is 3(r-20)(r+20); so
3*1200(r+20) + 3*1200(r-20)=19(r-20)(r+20)
3600r+7200+3600r-7200=19(r[squared]-400)
7200r=?
I am stuck at this point.