Subtract 7/21 from 27/42
27/42 - 7/21 is 13/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
27/42 = 27 × 1/42 × 1 = 27/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
7/21 = 7 × 2/21 × 2 = 14/42 - Subtract the two like fractions:
27/42 - 14/42 = 27 - 14/42 = 13/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/42-7/21 27/42-14/21 27/84-7/21 27/42-7/42 81/42-7/21 27/42-7/63 27/42-35/21 27/42-49/21