Word problem

Question

On the farm there are 78 feet and 28 heads, how many are chickens and how many are pigs?

Answer 1

P= pig 

c= chicken 

 

4p+2c = 78

p+c= 28 

 

Use U substitution 

 

c=-p+28 

 

4p+2(-p+28) =78

4p-2p+56=78

2p=22

p=11

 

11+c=28

c=17

 

11 pigs and 17 chickens.