Subtract 1/21 from 7/72
7/72 - 1/21 is 25/504.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 21 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
7/72 = 7 × 7/72 × 7 = 49/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
1/21 = 1 × 24/21 × 24 = 24/504 - Subtract the two like fractions:
49/504 - 24/504 = 49 - 24/504 = 25/504
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/72-1/21 7/72-2/21 7/72-1/42 21/72-1/21 7/72-3/21 7/72-1/63 35/72-1/21 7/72-5/21 49/72-1/21 7/72-7/21