1. a ball is thrown into the air. the height in feet of the ball can be modeled by the equation h = -16t2 + 20t + 6 where t is the time in seconds, the ball is in the air. when will the ball hit the ground? how high will the ball go?

and show all work.

Im thinking the ball will hit the ground in 8 seconds. times that and u get 16. im sorry if im wrong
 

You want to know the times when h = 0

So set the equation equal to 0

0 = -16t^2 + 20t + 6
16t^2 - 20t - 6 = 0
2(8t^2 - 10t - 3) = 0
2(4t + 1)(t - 3) = 0
set each factor equal to 0
4t + 1 = 0                       t - 3 = 0
4t = -1                            t = 3 - how long when the ball hits the ground
t = -1/4 (not valid can't have negative time)