Subtract 81/16 from 21/28
1st number: 21/28, 2nd number: 5 1/16
21/28 - 81/16 is -69/16.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 16 is 112
Next, find the equivalent fraction of both fractional numbers with denominator 112 - For the 1st fraction, since 28 × 4 = 112,
21/28 = 21 × 4/28 × 4 = 84/112 - Likewise, for the 2nd fraction, since 16 × 7 = 112,
81/16 = 81 × 7/16 × 7 = 567/112 - Subtract the two like fractions:
84/112 - 567/112 = 84 - 567/112 = -483/112 - After reducing the fraction, the answer is -69/16
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28-81/16 21/56-81/16 21/28-81/32 63/28-81/16 21/84-81/16 21/28-81/48 21/28-81/80