Question

a model rocket is launched from ground level into the air. its height is y, in feet, after x seconds can be represented by the equation y=160x-5x sq. what is the elapsed time in seconds, from the time the rocket is launched until it reaches ground level again?

Answer 1

set
\[160x-5x^2=0\] and solve for \(x\)

Answer 2

start by factoring as
\[5x(80-x)=0\] and then it should be easy to solve

Answer 3

how do I solve for x