Subtract 27/40 from 21/28
21/28 - 27/40 is 3/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 40 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 28 × 10 = 280,
21/28 = 21 × 10/28 × 10 = 210/280 - Likewise, for the 2nd fraction, since 40 × 7 = 280,
27/40 = 27 × 7/40 × 7 = 189/280 - Subtract the two like fractions:
210/280 - 189/280 = 210 - 189/280 = 21/280 - After reducing the fraction, the answer is 3/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28-27/40 21/28-54/40 21/56-27/40 21/28-27/80 63/28-27/40 21/28-81/40 21/84-27/40