Answer: First option.
Step-by-step explanation:
Let be "x" the number of spaghetti dinner tickets sold and "y" the number of barbecue dinner tickets sold.
You know that 1 spaghetti dinner ticket costs $7.25; so the total amount of money earned selling these tickects can be represented with this expression:
[tex]7.25x[/tex]
Since 1 barbecue dinner ticket costs $8.75; the total amount of money earned selling them can be represented with this expression:
[tex]8.75y[/tex]
Knowing that the total amount of money the band raised was $2,790, we can write the following equation to represent this situation:
[tex]7.25x+8.75y=2,790[/tex]
The band sold twice as many spaghetti dinners as barbecue dinners, which means that the amount of spaghetti dinners sold was two times the amount of barbecue dinners sold.
This can be represented with this equation:
[tex]x=2y[/tex]
Therefore, the set of equations that can be used to find "x" and "y", is:
[tex]\left \{ {{x=2y} \atop {7.25x+8.75y=2,790}} \right.[/tex]