Question 1125958
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...jet stream is 100 miles per hour. Traveling with the jet​ stream, an airplane can fly 1800 miles in the same amount of time as it takes to fly 600 miles against the jet stream. 
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{{{1800/(r+100)=600/(r-100)}}}

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{{{18/(r+100)=6/(r-100)}}}

{{{3/(r+100)=1/(r-100)}}}

{{{3r-300=r+100}}}

{{{2r=400}}}

{{{highlight(r=200)}}}