Answer:
To raise exactly $240, the charity needs to sell 20 snacks.
Step-by-step explanation:
Let
s = number of seats sold
y = number of snacks sold
Seats cost $24 each, then s seats cost $24s.
Snacks cost an additional $6 each, then y snacks cost $6y.
In total, s seats and y snacks cost $(24s+6y).
The charity needs to raise $240 to consider this event a success, so
![24s+6y=240](https://tex.z-dn.net/?f=24s%2B6y%3D240)
If 5 seats are sold, then
![24\cdot 5+6y=240\\ \\120+6y=240\\ \\6y=240-120\\ \\6y=120\\ \\y=20](https://tex.z-dn.net/?f=24%5Ccdot%205%2B6y%3D240%5C%5C%20%5C%5C120%2B6y%3D240%5C%5C%20%5C%5C6y%3D240-120%5C%5C%20%5C%5C6y%3D120%5C%5C%20%5C%5Cy%3D20)
To raise exactly $240, the charity needs to sell 20 snacks.
To solve this problem graphically, plot the graph of the line
and find on this line point with s-coordinate 5. This is exactly point (5,20), so the charity needs to sell 20 snacks.