posted by taylor .
farmer joe needs cows pigs an chickens
cows cost 10.00 each and pigs cost .50 cents each,an chickens are 10 cents.he needs 100 animals an he only has 100 dollars .
let x=cow, y=pig, and z=chicken
10x + .5y +.1z = 100
x + y + z = 100
substitute & get the answer.