The Magic Carpet charges $90 for installation and $9 per square yard of carpeting. The Flying Carpet's installation price is $50 but the store charges $13 for each square yard. What equation can be used to find at what number of square yards of carpeting will the cost, including installation, be the same for both stores?

The equation to use is 90 + 9x = 50 + 13x

At 10 square yards of carpeting, the cost would be same for both store.

Step-by-step explanation:

Let number of square yards be "x"

Magic Carpets cost would be fixed 90 and variable 9 per sq. yd.

The equation would be:

90 + 9x

For Flying Carpet, the cost would be fixed 50 and variable 13 per sq. yd.

The equation would be:

50 + 13x

To find the sq. yd. needed for both cost to be same, we equate both cost equation and find x:

The equation is:

90 + 9x = 50 + 13x

Solving for x:

90 + 9x = 50 + 13x

13x - 9x = 90 - 50

4x = 40

x = 40/4

x = 10 sq. yards of carpeting.