a farmer raises chickens and cows. he has a total of 34 animals in his
barnyard. his six year old son came in one day all excited saying,"Daddy,
daddy, did you know all of your animals have a total of 110 legs.
Without using algebra:
If they were all chickens, there would be twice as many legs as heads or 68
legs. So all the extra legs, which is 110-68=42 extra legs, belong to the
cows. So since a cow has 2 extra legs that a chicken doesn't have, the number
of cows is half of 42 or 21. So the number of chickens is 34-21 or 13.
Using algebra:
Let x = the number of chickens and y = the number of cows.
CHICKENS + COWS = 34 ANIMALS
CHICKEN LEGS + COW LEGS = 110
x + y = 34
2x + 4y = 110
Solve that system and get the same answer.
Edwin