Answer:

The artists must sell 4 paintings to break even.
Explanation:
Let
be the number of paintings the artists must sell to break even.
Cost:
- The materials cost for each painting is 6, so
paintings will cost
dollars. - Each artist must pay a 33 both fee.
- The total cost is
dollars.
Income:
- Each painting is sold for 15, generating
dollars in total revenue. - However, the artist must donate 5% of their total sales to the school, which amounts to
dollars. - The artist's net income is
dollars.
Break-even point:
The artist breaks even when their income equals their cost, so:

Solving the equation:



Therefore, the artists must sell 4 paintings to break even.