1. a tree 5 ft tall grows an average of 8 in. each year. which equation models the trees height h after x years?
a) h = -8x – 5
b) h = 8x – 5
c) h = -8x + 5
d) h = 8x + 5

Well we know that it grows 8 in a year. so after 1 year has grown 1 * 8 and after 2 years 2 * 8 and after 3 years 3 * 8 and so on. since x is the year we can say 8x. but it starts with 5 ft so we add in the 5 to get h.
h = 8x + 5