Question 98560
F+B=900 OR F=900-B
12F+10B=9780 NOW REPLACE F IN THIS EQUATION BY (900-B) & SOLVE FOR F.
12(900-B)+10B=9780
10800-12B+10B=9780
-2B=9780-10800
-2B=-1020
B=-1020/-2
B=510 BALCONY TICKETS WERE SOLD.
900-510=390 FLOOR TICKETS WERE SOLD.
PROOF
12*390+10*510=9780
4680+5100=9780
9780=9780