Y=2/5xt 10 the rate of change and y intercept

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.

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.