Question 165404
If the formula R = -0.037t + 50.1 can be used to predict the world record in the 400 - meter dash t years after 1925, for what years will the world records be 47.6 seconds or less? 
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EQUATION:
47.6 >= -0.037t + 50.1
-0.037t <= 47.6-50.1
-0.037t <= -2.5
t >= 67.567
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Year?
year >= 1925+67.567 >= 1993
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Cheers,
Stan H.