9. Andrew was measuring the height of the tree in his yard. Four years after it was planted, the tree was 11 feet tall. Twelve years after the tree was planted, it was 21 feet tall. Assuming the tree was growing at a constant rate, create the equation that models that growth of the tree over time. Show or explain your reasoning. (HINT: Use the two points to find the slope and use point-slope form to create an equation.)

Answer:Step-by-step explanation:Answer:Step-by-step explanation: