Solutions by everydaycalculation.com
221 - 721 is -521.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/21-7/21 2/21-14/21 2/42-7/21 2/21-7/42 6/21-7/21 2/63-7/21 2/21-7/63 10/21-7/21 2/21-35/21 14/21-7/21 2/21-49/21
© everydaycalculation.com