Solutions by everydaycalculation.com
1521 - 1821 is -17.
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21-18/21 15/21-36/21 15/42-18/21 15/21-18/42 45/21-18/21 15/21-54/21 15/63-18/21 15/21-18/63 75/21-18/21 15/21-90/21
© everydaycalculation.com