SOLUTION: A missile fired straight up into the air has a height, in meters, given by h = -5 t^2 + 40 t, where t is the time, in seconds, the missile has been in the air. By setting up an

Question 864321: A missile fired straight up into the air has a height, in meters, given by h = -5 t^2 + 40 t, where t is the time, in seconds, the missile has been in the air.
By setting up and solving an equation, find the times when the missile reaches a height of 60 meters.
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
h = -5 t^2 + 40 t
we have to calculate times when h=60
60=-5t^2+40t
5t^2-40t+60=0
/5
t^2-8t+12=0
t^2-6t-2t+12=0
t(t-6)-2(t-6)=0
(t-2)(t-6)=0
either (t-2)=0 OR (t-6) =0
t= 2 , t =6
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