Subtract 16/81 from 21/36
21/36 - 16/81 is 125/324.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 81 is 324
Next, find the equivalent fraction of both fractional numbers with denominator 324 - For the 1st fraction, since 36 × 9 = 324,
21/36 = 21 × 9/36 × 9 = 189/324 - Likewise, for the 2nd fraction, since 81 × 4 = 324,
16/81 = 16 × 4/81 × 4 = 64/324 - Subtract the two like fractions:
189/324 - 64/324 = 189 - 64/324 = 125/324
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/36-16/81 21/36-32/81 21/72-16/81 63/36-16/81 21/36-48/81 21/36-80/81