Answer:
10 years
Step-by-step explanation:
We are told that One year after you buy a tree, it is 10 feet tall. Thus, it's initial height after 1 year is 10 ft.
Now we are told that each year after you buy the tree, it grows 2 feet. This means that it's height after you bought it was; f(0) = 10 - 2 = 8ft
Thus,
f(1) = 8 + 2 = 10
f(2) = 8 + 2 + 2 = 12
f(3) = 8 + 2 + 2 + 2 = 14
The pattern here is;
f(x) = 8 + 2x
Where x is number of years
Thus, for it to reach a maximum height of 28 ft;
28 = 8 + 2x
Subtract 8 from both sides to give;
28 - 8 = 2x
2x = 20
x = 20/2
x = 10 years
