Answer:
System of Equations
c + r = 32 ..... Equation 1
2c + 4r = 72......... Equation 2
We have 28 chickens and 4 rabbits
Step-by-step explanation:
Let the number of chickens be represented by c
The number of rabbits be represented by r
From the question, John counts:a total of 32 heads
32 heads = a total of 32 animals
Hence:
c + r = 32....... Equation 1
c = 32 - r
Also, John counts:
A total of 72 legs in his backyard.
Chickens have: 2 legs
Rabbits have: 4 legs
Hence:
2c + 4r = 72......... Equation 2
System of Equations is:
c + r = 32 ..... Equation 1
2c + 4r = 72......... Equation 2
Lets us substitute 32 - r for c in Equation 2
2(32 - r) + 4r = 72
64 - 2r + 4r = 72
Collect like terms
- 2r + 4r = 72 - 64
2r = 8
r = 8/2
r = 4
This means we have 4 rabbits
Note:
c = 32 - r
r = 4
c = 32 - 4
c = 28
Hence, we have 28 chickens