SOLUTION: how do i write the quadratic equation used to find the time when the rocket reaches 80 ft. if y=55+33t-5t^2 where y is the height and t is the tim ethe rocket has been in the air?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: how do i write the quadratic equation used to find the time when the rocket reaches 80 ft. if y=55+33t-5t^2 where y is the height and t is the tim ethe rocket has been in the air?      Log On


   

Question 43: how do i write the quadratic equation used to find the time when the rocket reaches 80 ft. if y=55+33t-5t^2 where y is the height and t is the tim ethe rocket has been in the air?
Answer by ichudov(507) About Me  (Show Source):
You can put this solution on YOUR website!
Very simple. The problem says that y is height. So, put word height instead of y:
height=55%2B33t-5t%5E2+
Since the problem tells you that height is 80 feet, you have
80=55%2B33t-5t%5E2+
or
-5t%5E2%2B33t%2B55-80=0
that is your quadratic equation.