Subtract 7/18 from 21/7
1st number: 3 0/7, 2nd number: 7/18
21/7 - 7/18 is 47/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 7 × 18 = 126,
21/7 = 21 × 18/7 × 18 = 378/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
7/18 = 7 × 7/18 × 7 = 49/126 - Subtract the two like fractions:
378/126 - 49/126 = 378 - 49/126 = 329/126 - After reducing the fraction, the answer is 47/18
- In mixed form: 211/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7-7/18 21/7-14/18 21/14-7/18 21/7-7/36 63/7-7/18 21/7-21/18 21/7-7/54 21/7-35/18 21/35-7/18 21/7-7/90 21/7-49/18 21/49-7/18