Subtract 49/40 from 7/21
1st number: 7/21, 2nd number: 1 9/40
7/21 - 49/40 is -107/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
7/21 = 7 × 40/21 × 40 = 280/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
49/40 = 49 × 21/40 × 21 = 1029/840 - Subtract the two like fractions:
280/840 - 1029/840 = 280 - 1029/840 = -749/840 - After reducing the fraction, the answer is -107/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-49/40 7/21-98/40 7/42-49/40 7/21-49/80 7/63-49/40 35/21-49/40 49/21-49/40