Ineed some here i'm not sure what to do. in advance.

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

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.

Find the value of x. give reasons to justify your solutions! l, m ∈ kn