Subtract 25/40 from 7/21
7/21 - 25/40 is -7/24.
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,
25/40 = 25 × 21/40 × 21 = 525/840 - Subtract the two like fractions:
280/840 - 525/840 = 280 - 525/840 = -245/840 - After reducing the fraction, the answer is -7/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-25/40 7/21-50/40 7/42-25/40 7/21-25/80 7/21-75/40 7/63-25/40 35/21-25/40 49/21-25/40