Shivani is making greeting cards, which she will sell by the box at an arts fair. She paid $20 for a booth at the fair, and the materials for each box of cards cost $5. She will sell the cards for $7 per box of cards. At some point, she will sell enough cards so that her sales cover her expenditures. How many cards will that take?

10 cards

Step-by-step explanation:

So to do this problem, you can make an equation where x is the number of cards sold, which would be:

7x - 20 - 5x = 0

This is because she makes $7 for every card she sells (so 7x), she paid $20 for the booth (so -20), it costs her $5 to make every card (so -5x), and you want to see how many cards it will take for her to cover everything she spent (so it would equal 0).

Then, solving:

combine like terms

add 20 to both sides

divide both sides by 2

This means the answer is 10 cards

hope this is what you were asking for!

step-by-step explanation: