Subtract 27/40 from 3/21
3/21 - 27/40 is -149/280.
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,
3/21 = 3 × 40/21 × 40 = 120/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
27/40 = 27 × 21/40 × 21 = 567/840 - Subtract the two like fractions:
120/840 - 567/840 = 120 - 567/840 = -447/840 - After reducing the fraction, the answer is -149/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21-27/40 3/21-54/40 3/42-27/40 3/21-27/80 9/21-27/40 3/21-81/40 3/63-27/40 15/21-27/40