Subtract 3/9 from 9/21
9/21 - 3/9 is 2/21.
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,
9/21 = 9 × 3/21 × 3 = 27/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
3/9 = 3 × 7/9 × 7 = 21/63 - Subtract the two like fractions:
27/63 - 21/63 = 27 - 21/63 = 6/63 - After reducing the fraction, the answer is 2/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/21-3/9 9/21-6/9 9/42-3/9 9/21-3/18 27/21-3/9 9/63-3/9 9/21-3/27 45/21-3/9 9/21-15/9 9/21-3/45 63/21-3/9 9/21-21/9 9/21-3/63