What is the midpoint between -11 and 26 on the number line? 15 8.5 7.5 18.5

Anyone know? will mark brainliest if correct!

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.

Can someone me out here and the tell me the greatest common factor