Subtract 9/7 from 9/21
1st number: 9/21, 2nd number: 1 2/7
9/21 - 9/7 is -6/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
9/21 = 9 × 1/21 × 1 = 9/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
9/7 = 9 × 3/7 × 3 = 27/21 - Subtract the two like fractions:
9/21 - 27/21 = 9 - 27/21 = -18/21 - After reducing the fraction, the answer is -6/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/21-9/7 9/21-18/7 9/42-9/7 9/21-9/14 27/21-9/7 9/21-27/7 9/63-9/7 9/21-9/21 45/21-9/7 9/21-45/7 9/21-9/35 63/21-9/7 9/21-63/7 9/21-9/49