Answer:
money = 2×tickets
Explanation:
For 1 ticket sold, $2 is collected. for 8 tickets sold, $16 is collected. The relationship appears to be proportional with a constant of proportionality of $2 per ticket.
The axes are labeled "money" and "tickets", so we can write the equation ...
money = 2×tickets . . . . . where money is in dollars
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If you like, you can use y to represent dollars collected, and x to represent tickets sold. Then the equation is ...
y = 2x