Cynthia Sold 348 Tickets To The School Basketball Game. Tickets Cost $1.25 For People With An Activity Pass And $3.00 Without The Activity Pass. The Total Receipts For The Game Were $613.50. How Many People Buying Tickets Had An Activity Pass?

If a tickets were sold with an activity pass, Cynthia's revenue was
  a*1.25 + (348 - a)*3.00 = 613.50
  -1.75a + 1044.00 = 613.50    (use the distributive property, collect terms)
  -1.75a = -430.50    (subtract 1044)
  a = 246    (divide by -1.75)

246 tickets were sold to people with an activity pass.