Question 1173134
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Hi, 
h=45-5t-5t^2
How long after the ball is thrown does it hit the ground?
h = 0
5t^2 + 5t - 45 = 0
t^2 + t - 9 = 0
{{{t = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{t = (-1 +- sqrt( 1^2 + 36 ))/(2) }}}
{{{t = (-1 + sqrt( 37))/(2) }}}  Throwing out the negative solution for time
 t = 2.5414s
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