Subtract 4/9 from 7/21
7/21 - 4/9 is -1/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
7/21 = 7 × 3/21 × 3 = 21/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
4/9 = 4 × 7/9 × 7 = 28/63 - Subtract the two like fractions:
21/63 - 28/63 = 21 - 28/63 = -7/63 - After reducing the fraction, the answer is -1/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-4/9 7/21-8/9 7/42-4/9 7/21-4/18 7/21-12/9 7/63-4/9 7/21-4/27 35/21-4/9 7/21-20/9 7/21-4/45 49/21-4/9 7/21-28/9 7/21-4/63