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

Algebra ->  Average -> SOLUTION: The formula R = -0.075 + 3.85 can be used to predict the world record in the 1500 meter run, t years after 1930. Dertermine an inequality that identifies the years in which the wor      Log On


   

Question 532053: The formula R = -0.075 + 3.85 can be used to predict the world record in the 1500 meter run, t years after 1930. Dertermine an inequality that identifies the years in which the world record will be < 3.7 minutes. t < ___ ? I have been bandging my head, and just cannot getthe formula, sorr to be so duh! Thanks...... have a good one
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The formula R = -0.075 + 3.85 can be used to predict the world record in the 1500 meter run, t years after 1930. Determine an inequality that identifies the years in which the world record will be < 3.7 minutes. t < ___ ?
:
Assume the formula is:
R = -0.075t + 3.85
:
-.075t + 3.85 < 3.7 min
-.075t < 3.7 - 3.85
-.075t < -.15
t had to be positive, multiply both sides by -1, this reverses the inequality sign
.075t > .15
t > .15%2F.075
t > 2 yrs
Add that to 1930, we can say it will be less than 3.7 min after 1932
:
:
We can confirm that by finding the time in 1933 (t=3)
R = -0.075(3) + 3.85
R = -.225 + 3.85
R = 3.625 min, slightly less than 3.7
:
:
Hey! I have not heard that one before, does bandaging your head actually help?