SOLUTION: The formula R= -0.075t+3.85 can be used to predict the world record in the 1500 meter run, t years agter 1930. Determining an inequality that identifies the years in which the worl

Algebra ->  Algebra  -> Customizable Word Problem Solvers  -> Finance -> SOLUTION: The formula R= -0.075t+3.85 can be used to predict the world record in the 1500 meter run, t years agter 1930. Determining an inequality that identifies the years in which the worl      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com
Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!
Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

   

Question 134857: The formula R= -0.075t+3.85 can be used to predict the world record in the 1500 meter run, t years agter 1930. Determining an inequality that identifies the years in which the world record will be less than 2.8 minutes. Sovle for t. Thanks for your time.
Found 2 solutions by vleith, stanbon:
Answer by vleith(2517) About Me  (Show Source):
You can put this solution on YOUR website!
Given: R=+-0.075t%2B3.85+
At some year, the time will get below 2.8 minutes
2.8+%3E+-0.075t%2B3.85+
%282.8-3.85%29+%3E+-0.075t+
Remember to swap the sign when multiplying or dividing by a negative
+%28%28-1.05%29%2F%28-0.075%29%29+%3C+t+
+14+%3C+t+
So any year > 1930 + 14 will do it
+t+%3E+1944+

Answer by stanbon(48558) About Me  (Show Source):
You can put this solution on YOUR website!
The formula R= -0.075t+3.85 can be used to predict the world record in the 1500 meter run, t years after 1930. Determining an inequality that identifies the years in which the world record will be less than 2.8 minutes. Solve for t. Thanks for your time.
------------------------------
2.8 > -0.075t+3.85
-0.075t < -1.05
t > 14
--------------
R will be less than 2.8 after 1930+14 = 1944
==========================
Cheers,
Stan H.