SOLUTION: please help solve this problem h(t) = -16t2 + 64t + 160 Find the times when the rocket will be 40 feet from the ground

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Question 763740: please help solve this problem h(t) = -16t2 + 64t + 160 Find the times when the rocket will be 40 feet from the ground
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
-16t%5E2+%2B+64t+%2B+160=40
-16t%5E2+%2B+64t+%2B+120=0 divide by -8
2t%5E2+-8t+-+15=0
t=%28-%28-8%29%2B-sqrt%288%5E2-4%2A2%2A%28-15%29%29%29%2F%282%2A2%29


t=5.391 sec