Atree 7 ft tall grows an average of 6 in. each year. which equation models the tree’s height h after x years?

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.