We have a system of two equations. x - the number of rabbits y - the number of chickens
Both chicken and rabbit have only 1 head, so the first equation is: x + y = 72. Since rabbits have 4 legs and chickens 2 legs, the second equation is: 4x + 2y = 200.
Now, let's solve the system: x + y = 72 4x + 2y = 200 ___________ y = 72 - x ⇒ 4x + 2 · (72 - x) = 200 4x + 2 · 72 - 2 · x = 200 4x + 144 - 2x = 200 2x + 144 = 200 2x = 200 - 144 2x = 56 ⇒ x = 56 ÷ 2 = 28 So, there are 28 rabbits.
Since y = 72 - x = 72 - 28 = 44, there are 44 chickens.
