SOLUTION: The mass (in Mg) of the fuel supply in the first-stage booster of a rocket is m = 135 - 6t - t^2, where is the time ( in s) after launch. When does the booster run out of fuel

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Question 957164: The mass (in Mg) of the fuel supply in the first-stage booster of a rocket is m = 135 - 6t - t^2, where is the time ( in s) after launch. When does the booster run out of fuel
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
135+-+6t+-+t%5E2=0
t%5E2%2B6t-135=0
%28t-9%29%28t%2B15%29=0
Only positive t makes sense here.
t-9=0
t=9s