Subtract 21/49 from 28/40
28/40 - 21/49 is 19/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 49 is 1960
Next, find the equivalent fraction of both fractional numbers with denominator 1960 - For the 1st fraction, since 40 × 49 = 1960,
28/40 = 28 × 49/40 × 49 = 1372/1960 - Likewise, for the 2nd fraction, since 49 × 40 = 1960,
21/49 = 21 × 40/49 × 40 = 840/1960 - Subtract the two like fractions:
1372/1960 - 840/1960 = 1372 - 840/1960 = 532/1960 - After reducing the fraction, the answer is 19/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40-21/49 28/40-42/49 28/80-21/49 28/40-21/98 84/40-21/49 28/40-63/49