Question

In certain county, the number of charter schools is 4 less than twice the numbervof alternative schools. We know that there are 48 charter schools in the county. How many alternative schools are in the county?

Answer 1

1. Let's call the number of carter school: "x" and "y" the number of alternative school.  Then, you have that:

 - The number of charter schools is 4 less than twice the number of alternative schools.
 - There are 48 charter schools in the country.

 2. So, you have:

 x=2y-4  (i)

 x=48  (ii)

 3. Then, when you substitute x=48 into the equation (i), you obtain:

 x=2y-4
 48=2y-4

 4. Now, you must clear "y, as below:

 48+4=2y
 2y=52
 y=52/2
 y=26
 
 How many alternative schools are in the county?

 The answer is: There are 26 alternative schools.