In Farmland, one cow can be exchanged for two goats, and three goats
can be exchanged for five chickens. How many chickens can six cows
be exchanged for?
1c = 2g
or c = 2g
3g=5f (f= chickens)
g=5/3f Substitute into the first equation
c = 2 (5/3 f) now you have 6 cows so multiply both sides by 6
6c = (6)(2)(5/3 f) = 60/3 f = 20 f
6 cows = 20 chickens