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put this solution on YOUR website!From the given information we can say:

Where A is the advance ticket and S is the same-day ticket.
Solve the first equation for one of the variables:

Then plug this into the second equation:

Distribute the 20:

Move the 1200 to the other side and combine the S terms:

Divide both sides by 10:

Plug this back into our first equation:

So, 40 same-day tickets were sold and 20 advance tickets.