There are 300 people at a play. some paid $5.00 for reserved seats; others paid $3.00 for general admission seats. total receipts were $1080. how many tickets of each kind were sold?

R+g=300, r=300-g

5r+3g=1080, using r found above in this you get:

5(300-g)+3g=1080

1500-5g+3g=1080

1500-2g=1080

-2g=-420

g=210, since r=300-g

r=90

So 90 reserved and 310 general tickets were sold.