Need help figuring out the equation you'd get from the following paragraph...

A Broadway performance of The Phantom of the Opera had a paid attendance of 320 people. Balcony tickets cost 42$, and orchestra tickets cost 64$. Ticket sales receipts totaled 16,630$. How many tickets of each type were sold?

I seem to have forgotten how I'd write this as an equation... I don't want to have the equation solved (yet, I'll see if I can get it on my own) but I've spent the last 20 minutes trying to find a way to make equations to help figure it out. I have to use a system of two linear equations to solve it, either addition method or substitution method.

Thank you for any help.