Question

A water balloon is thrown from a window. The height of the balloon can be found using the equation
y=-7.5x+45, where x
is the time in seconds the balloon has been in the air.

How many seconds will it take for the balloon to hit the ground?

Answer 1

Set y = 0 and solve:

0 = −7.5x + 45
7.5x = 45
x = 45 / 7.5 = 6

So the balloon hits the ground after 6 seconds.