Solutions by everydaycalculation.com
621 - 721 is -121.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 12/21-7/21 6/21-14/21 6/42-7/21 6/21-7/42 18/21-7/21 6/63-7/21 6/21-7/63 30/21-7/21 6/21-35/21 42/21-7/21 6/21-49/21
© everydaycalculation.com