Subtract 3/28 from 21/42
21/42 - 3/28 is 11/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
21/42 = 21 × 2/42 × 2 = 42/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
3/28 = 3 × 3/28 × 3 = 9/84 - Subtract the two like fractions:
42/84 - 9/84 = 42 - 9/84 = 33/84 - After reducing the fraction, the answer is 11/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42-6/28 21/84-3/28 21/42-3/56 63/42-3/28 21/42-9/28 21/42-3/84 21/42-15/28 21/42-21/28