Answer:
It took 8 seconds for the leaf to reach the ground.
Explanation:
The height of the leaf in feet can be found using the function:
y = -3.5*x + 28
where x is the time in seconds the leaf has been in the air.
You want to know how long it took for the blade to reach the ground. That is, the time it took for the blade to reach a height of 0 feet. So, replacing this value in the expression:
0= -3.5*x + 28
and solving you get:
-28= -3.5*x
(-28)÷ (-3.5)=x
8=x
It took 8 seconds for the leaf to reach the ground.