Answer:
35 adults, 420 children
Explanation:
1. Set up variables
Let's say children is c and adults is a.
2. Create the equations
c = 12a AND c + a = 455
3. Plug in the variables
Let's take c = 12a and substitute it in for c in the equation "c + a = 455." That would be...
12a + a = 455
13a = 455
a = 35
3. Plug in more variables
Now we have our answer for a, so let's plug it into the other equation. That would be...
c + a = 455
c + 35 = 455
c = 420