Subtract 6/21 from 21/72
21/72 - 6/21 is 1/168.
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,
21/72 = 21 × 7/72 × 7 = 147/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
6/21 = 6 × 24/21 × 24 = 144/504 - Subtract the two like fractions:
147/504 - 144/504 = 147 - 144/504 = 3/504 - After reducing the fraction, the answer is 1/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/72-6/21 21/72-12/21 21/72-6/42 63/72-6/21 21/72-18/21 21/72-6/63 21/72-30/21 21/72-42/21