Question

Theater tickets are $8 for general admission and $5 for students. During one evening 240 tickets were sold, and the receipts were $1680. How manny of each ticket was sold?

This is what I have before I get stuck:
G=8 S=5
8(240-S)+5S=1680
1920-S+5S=1680
Now what?

Answer 1

Move 1920 to right side (making it negative 1920), combine the S terms (but you have made an error [the 1920-S should be 1920-8S)], and calculate S, then G. You have worked the problem as if G is the NUMBER of $8 tickets sold and S is the NUMBER of $5 tickets sold.
That way G + S = 240 tickets (the total tickets sold).
I worked it out for S = 80 tickets but check my work.