Question 206657
The formula R= 0.075t + 3.85 can be used to predict the world record in the 1500-m run t years after 1930. Determine (in terms of an inequality) those years for which the world record will be less than 3.5 min.
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0.075t + 3.85 < 3.5
0.075t < -0.35
t < -4 2/3
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I think you have not posted the problem correctly.
The answer implies the record willth wil less than 
3.5 min any year after 1930-4 2/3 or the year 1925.
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Cheers,
Stan H.