Answer:


Demarco can make 45 medium-sized collars and 55 large-sized collars.
Explanation:
Let's use the following variables:
- x = number of medium-sized collars
- y = number of large-sized collars
- c = number of ID tags
We know that the cost for making dog collars is $8 for every medium-sized collar and $12 for every large-sized collar.
We also know that Demarco wants to make a total of 100 dog collars. This gives us the following system of linear equations:


To find how many of each size collar Demarco can make, we can solve the system of equations.
We can do this by subtracting the second equation from the first equation by substitution or elimination. Let's use the substitution method.
From Equation 2,
solve for x:

Substitute this value of x into Equation 1:

Open bracket on left side

Solve like terms,

Subtract both sides by 800,


Divide both side by 4.


Now that we have the value of y (number of large-sized collars), substitute it back into the expression for x:



So, Demarco can make 45 medium-sized collars and 55 large-sized collars.