Respuesta :

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