Subtract 7/72 from 20/42
20/42 - 7/72 is 191/504.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 42 × 12 = 504,
20/42 = 20 × 12/42 × 12 = 240/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
7/72 = 7 × 7/72 × 7 = 49/504 - Subtract the two like fractions:
240/504 - 49/504 = 240 - 49/504 = 191/504
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-7/72 20/42-14/72 20/84-7/72 60/42-7/72 20/42-21/72 20/42-35/72 20/42-49/72