Answer:
The number of cows on Justin's farm is 18.
Step-by-step explanation:
Given:
The only animals on farmer Justin's farm are cows and chickens.
Justin counts a total of 45 heads and a total of 126 feet.
Now, to find the number of cows on Justin's farm.
Let the number of cows be [tex]a.[/tex]
And the number of chickens be [tex]b.[/tex]
So, the total number of heads are:
[tex]a+b=45[/tex]
[tex]b=45-a[/tex] .......(1)
As, the feet of chicken are 2 and the cows are 4.
Thus, total number of feet are:
[tex]4a+2b=126[/tex]
Substituting the value of from equation (1) we get:
[tex]4a+2(45-a)=126[/tex]
[tex]4a+90-2a=126\\2a+90=126[/tex]
Subtracting both sides by 90 we get:
[tex]2a=36[/tex]
Dividing both sides by 2 we get:
[tex]a=18.[/tex]
The number of cows = 18.
Therefore, the number of cows on Justin's farm is 18.
