The initial height of the tree = 7 ft
Each year the tree grows 6 in. 6 in = 6 / 12 = 0.5 ft
So the tree grows 0.5 ft every year.
After x years, the tree would have grown extra = 0.5*x =0.5x
So the height of the tree would be = Initial height + extra height grown
= 7 + 0.5x
h = 7 + 0.5x
Model is h = 7 + 0.5x,
where h = height of the tree in feet after x years.
Hope this explains it.
