Question

Suppose you are determining the growth rate of two species of plants. Species A is 12 cm tall and grows 2 cm per month. Species B is 10 cm tall and grows 3 cm per month. Which system of equations models the height of each species H(m) as a function of months m.

Answer 1

Species A: H(m) = 12+2m

Species B: H(m) = 10+3m

Step-by-step explanation:

Remember, the question asks you for the function of months, not days. If it were in days, the first response you got would work. This is a simple transfer from words to numbers equation.

Answer 2

This is how to solve the problem:

We know that the growth rate is constant for both species of plants. So we can say that the height is a linear function of the number of days since d = 0.

Assumption (1 month = 30 days)

Species A:
Growth rate = 2 cm/month = 2/30 = 1/15 cm/day
Height on day d = 0: 12 cm
Height: H(d) = 12 + d/15

Species B:
Growth rate = 3 cm/month = 3/30 = 1/10 cm/day
Height on day d = 0: 10 cm
Height: H(d) = 10 + d/10