
Bobosharif S. answered 02/14/18
Tutor
4.4
(32)
Mathematics
There are 500 tickets; let's denote by x the number of tickets to be sold for $9, befoe the day of concert and y the number of tickets for $12 on the day of concert. It is clear that x+y=500. Organizers would like to raise revenue at lleast to $5,700, that is $9x+$12y≥$5,700.
So we have the following:
x+y=500
9x+12y≥5,700.
3y≥5700-4500
3y≥1200
y≥400
x≥100