Sharon runs a screen-printing business. To print T-shirts each day, it costs her $200 in labor plus $5 per T-shirt for materials. Her income is $15 for each T-shirt she sells. How many T-shirts does Sharon need to sell each day in order for her costs to equal her income for that day?

(i mainly need the equation for this problem)

We need to find an expression for the costs for 1 day for making n number of T-shirts and an expression for the income for 1 day for selling n number of T-shirts. Then we set the expressions equal and solve for n, the number of T-shirts.

Expenses in 1 day:

The expenses are a fixed cost of $200 plus the cost per T-shirt.

$200 plus $5 per T-shirt

We need an expression for the cost per T-shirt in terms of n, the number of T-shirts.

If she makes 1 T-shirt, she spends $5 * 1.

If she makes 2 T-shirts, she spends $5 * 2.

If she makes n T-shirts, she spends $5 * n, or simply 5n.

Her total costs for a day are:

200 + 5n

Income in 1 day:

All the income comes from selling T-shirts.

She sells 1 T-shirt for $15 * 1.

She sells 2 T-shirts for $15 * 2.

She sells n T-shirts for $15 * n, or simply 15n

Her total income for 1 day is:

15n

Now we set the costs equal to the income and solve for n.

15n = 200 + 5n <--------- here is the equation you need

Subtract 5n from both sides.

10n = 200

Divide both sides by 10.

n = 20

Answer: She needs to sell 20 T-shirts.