What is this question to the nearest mile ?

The height of a flare fired from the deck of a ship in distress can be modeled by h(t)= -2(8t^2-52t-28), where h is the height of the flare above water and t is the time in seconds. a. find the time it takes the flare to hit the water.

Combine the information in the problem and the chart using the average balance method to solve the problem.

With finding limits of multi variable !