A man buys 4 cows and 9 goats for $50, 150. If he had purchased 9 cows and 4 goats, instead, then he would have to pay $40,750 more. What is the cost of one cow?
For this one, we need to set up a system of equations. Let cow be c, and goat be g. So:
4c+9g=50150
9c+4g=91900
So, what can we do here? Well, if we add them two together, we get:
13c+13g=141050
Divide by 13:
c+ g = 10850
Now, what can we do? Well we subtract the two equations:
-5c + 5g = -40750
Divide by -5:
c - g = 8150
Now, add the two equations that we made together:
2c=19000
c=9500
please correct me if I'm wrong.
:)