Mandy has 50 yards of fabric to make costumes for a play. She makes 12 skirts that take 3 yards each, and 9 hats that each take 1 yard. Which expression represents the number of yards of fabric that are left?

The equation would be 12 (3) + 9 (1) - 50=?

Because if she makes 12 skirt that take 3 yards each, you multiply that to know how many yards the skirts take. Then you multiply 9 by 1 to find the yards that the hats use. Then you subtract the those from the total to get what is left over.

12 (3) + 9 (1) - 50=?

36+9-50=?

45-50=?

The answer is 5 yards left over