After the first day of ticket sales for the annual school play, members of the Drama Club and Stage Crew determined that they sold a total of 14 tickets and collected a total of $78. They knew that student tickets sold for $5 each and adult tickets sold for $7 each, but they were unsure about how many of each were sold.
Write a system of equations that represent the constraints described above. Define any variables that you use
adult tickets --- x
student tickets ---- y
x+y = 14
7x + 5y = 78