Answer:
The System of equations are

There were 22375 adults and 15625 children attended the soccer match.
Explanation:
Given,
Total number of people attending the soccer match = 38000
Let the number of adults be 'x'.
Let the number of Children be 'y'.
So Total number of people attending the soccer match is equal to sum of the number of adults and the number of Children.
framing in equation form we get;

Also Given:
Cost of Adult ticket = $8
Cost of Children ticket = $5
Total Sales = $257,125
So we can say that Total Sales is equal to the number of adults multiplied by Cost of Adult ticket and the number of Children multiplied by Cost of Children ticket.
framing in equation form we get;

So The System of equations are

On Solving the above system of equation we get
Now Multiplying equation 1 with 5 we get;

Now Subtracting equation 3 from equation 2 we get;

Now Substituting the value of x in equation 1 we get;

Hence There were 22375 adults and 15625 children attended the soccer match.