SOLUTION: Please help me sole this problem: There are 13 animals in a barn. Some are chickens and some are pigs. There are 40 legs in the barn. How many are there of each animal?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Please help me sole this problem: There are 13 animals in a barn. Some are chickens and some are pigs. There are 40 legs in the barn. How many are there of each animal?      Log On


   



Question 486431: Please help me sole this problem:
There are 13 animals in a barn. Some are chickens and some are pigs. There are 40 legs in the barn. How many are there of each animal?

Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
Let x chickens
Let y pigs
Then x%2By=13
The animals have 2x%2B4y legs, so 2x%2B4y=40
The system of the equations
system+%28x%2By=13%2C+2x%2B4y=40%29
divide the second equation by 2
system+%28x%2By=13%2C+x%2B2y=20%29
Subtract the first equation from the second one
y=20-13
y=7 pigs
Substitute y=7 into the first equation
x%2B7=13
x=13-7
x=6 chickens