Subtract 7/8 from 21/54
21/54 - 7/8 is -35/72.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 8 is 216
Next, find the equivalent fraction of both fractional numbers with denominator 216 - For the 1st fraction, since 54 × 4 = 216,
21/54 = 21 × 4/54 × 4 = 84/216 - Likewise, for the 2nd fraction, since 8 × 27 = 216,
7/8 = 7 × 27/8 × 27 = 189/216 - Subtract the two like fractions:
84/216 - 189/216 = 84 - 189/216 = -105/216 - After reducing the fraction, the answer is -35/72
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/54-7/8 21/54-14/8 21/54-7/16 63/54-7/8 21/54-21/8 21/54-7/24 21/54-35/8 21/54-7/40 21/54-49/8 21/54-7/56