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A trip of 900 miles would have taken 1 hour less if the average speed
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02 Dec 2023, 09:41
We can interpret into this equation, where r = average speed for the trip.
\(\frac{900}{r }- 1 =\frac{ 900}{r+10}\)
= \(\frac{900-r}{r}\)
Cross-multiply to set up:
\(900-r(r+10) = 900r\)
\(900r+9000-r^2-10r = 900r\)
\(r^2+10r-9000=0\)
\((r+100)(r-90)=0\)
Since r can't be a negative value, the answer is 90.