Answer:
27 Chickens
Step-by-step explanation:
Represent the chicken with A and the cows with B
Given
[tex]A + B = 30[/tex]
A has 2 legs and B has 4; So:
[tex]2A + 4B = 66[/tex]
Required
Determine A and B
Make B the subject of formula in the first equation
[tex]B = 30 - A[/tex]
Substitute 30 - A for B in the second equation
[tex]2A + 4(30 - A) = 66[/tex]
Open the bracket
[tex]2A + 120 - 4A = 66[/tex]
Collect Like Terms
[tex]2A - 4A = 66 - 120[/tex]
[tex]-2A= -54[/tex]
Divide through by -2
[tex]A = 27[/tex]
Hence, the farmer has 27 chickens