The formula R = -0.075t+3.85 can be used to predict the world record in the 1500 meter run, t years after 1930. Determine an inequality that world record will be less than 2.8 minutes.
Solve for t.
If we ignore the total silliness of the question
-0.075t+3.85 < 2.8
t > 14
To determine the inequality, we need to set up the formula and solve for t when the world record time is less than 2.8 minutes.
Given: R = -0.075t + 3.85
We want to find t when R < 2.8.
Substitute R with 2.8 in the formula:
2.8 = -0.075t + 3.85
Rearrange the equation to isolate t:
-0.075t = 2.8 - 3.85
-0.075t = -1.05
Divide both sides of the equation by -0.075 to solve for t:
t = (-1.05) / (-0.075)
t = 14
Therefore, the world record will be less than 2.8 minutes when t is less than 14 years after 1930. In other words, the inequality is:
t < 14