Subtract 2/7 from 21/18
1st number: 1 3/18, 2nd number: 2/7
21/18 - 2/7 is 37/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 7 × 18 = 126,
2/7 = 2 × 18/7 × 18 = 36/126 - Subtract the two like fractions:
147/126 - 36/126 = 147 - 36/126 = 111/126 - After reducing the fraction, the answer is 37/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18-2/7 21/18-4/7 21/36-2/7 21/18-2/14 63/18-2/7 21/18-6/7 21/54-2/7 21/18-2/21 21/18-10/7 21/90-2/7 21/18-2/35 21/18-14/7 21/18-2/49