<PRE><B>Question 122443</B>
Let x be the number of tickets for Floor seats
    y be the number of tickets for Balcony seats

Equation:
             x +  y =  800
           10x + 8y = 7440

By substitution method
           x + y = 800   or x = 800 - y

Substitute to 10x + 8y = 7440
              10(800-y) + 8y = 7440
              8000 - 10y + 8y = 7440
                   -2y = 7400 - 8000
                   -2y = - 560
                     y = 280

If y = 280 then x = 800 - y, or x = 800 - 280
then x = 520

So there were 520 Floor seats sold</PRE>