Charla and David are observing the leaf growth rates of their plants. Charla’s plant starts on day 1 with 43 leaves and gets 1 new leaf a day. David’s plant starts on day 1 with 36 leaves and gets 2 leaves a day.
How many days will it take David’s plant to have as many leaves as Charla’s plant?

(A) 7

(B) 8

(C) 6

(D) 9

Question

Charla and David are observing the leaf growth rates of their plants. Charla’s plant starts on day 1 with 43 leaves and gets 1 new leaf a day. David’s plant starts on day 1 with 36 leaves and gets 2 leaves a day.
How many days will it take David’s plant to have as many leaves as Charla’s plant? 


 (A) 7 

 (B) 8 

 (C) 6 

 (D) 9

phi · Answer

notice that you can find the equation of a line for both plants.
they give you a point  (day, # of leaves)  and a "slope"  = # of new leaves per day.

can you write down the equation for Charla's plant and David's plant