I think that its 21.0648 im sorry if its not correct
The correct answer to your question is 15 days because if she drinks 1/3 of a can a day it will take 3 days to drink one can. Now multiple the 3 days for one can by the 5 cans and you get 15 days to finish all of the cans.
Eq1
Y intercept -2,0
X intercept 0,2
Slope 1
Eq2
X intercept-2,0
Y intercept 0,2
Slope 1
