SOLUTION: I have a problem on a homework assignment. The problem says: A farmhouse shelters 10 animals. Some are pigs and some are ducks. Together, there are 36 legs. How many of each are th

Algebra ->  Linear-equations -> SOLUTION: I have a problem on a homework assignment. The problem says: A farmhouse shelters 10 animals. Some are pigs and some are ducks. Together, there are 36 legs. How many of each are th      Log On


   

Question 751777: I have a problem on a homework assignment. The problem says: A farmhouse shelters 10 animals. Some are pigs and some are ducks. Together, there are 36 legs. How many of each are there?
Answer by FrankM(1040) About Me  (Show Source):
You can put this solution on YOUR website!
4P+2D=36 i.e. 4 times the number of pigs is the number of pig-feet, 2D = duck-feet
P+D=10 ten animals total.
Multiply second equation by 4:
4P+4D=40
4P+2D=36 (and subtract first equation.
2D=4
2 ducks, 8 pigs. 10 animals.
4 duck feet + 32 pig-feet, total 36 feet.