The formula R=-0.075 t 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 less than 3.1 minutes.

Answer 1

When the world record is less than 3.1, R is less than 3.1.

3.1 = -0.075t + 3.85

Solve for t (in years after 1930).