3. Tarzan went to the plant nursery and bought a tree that was initially 90 feet tall for his monkey friends to climb on. After planting the tree, Tarzan made a table to record the height, h, of the tree, t years after it was planted. “Zero” is the time when he planted the tree.
t 0 1 2 3 4
h 90 105 120 135 150

(a) Use words to describe the relationship between the height of the tree and the number of years since it was planted.

(b) Write a two-variable equation to illustrate the relationship between the height of the tree and the number of years since it has been planted.