Subtract 3/40 from 81/21
1st number: 3 18/21, 2nd number: 3/40
81/21 - 3/40 is 1059/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
81/21 = 81 × 40/21 × 40 = 3240/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
3/40 = 3 × 21/40 × 21 = 63/840 - Subtract the two like fractions:
3240/840 - 63/840 = 3240 - 63/840 = 3177/840 - After reducing the fraction, the answer is 1059/280
- In mixed form: 3219/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/21-6/40 81/42-3/40 81/21-3/80 81/21-9/40 81/63-3/40 81/21-15/40 81/21-21/40