What is -17 + 12 + 15?​

What is the answer to |-2x-5|-|-4+8| and x=7

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.

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?