Answer:
     8 cm
m = -------------- Â Â This is the desired rate of change, the amount the plant
     5 wk        grows per 1 week.
Step-by-step explanation:
Moving from point (0, 0) to point (5, 8), we see that the x-coordinate (the 'run') increases by 5 wk and the y-coordinate (the 'rise') increases by 8 cm. Â Thus we have the rate of change
     8 cm
m = -------------- Â Â This is the desired rate of change, the amount the plant
     5 wk        grows per 1 week.