Subtract 4/7 from 21/18
1st number: 1 3/18, 2nd number: 4/7
21/18 - 4/7 is 25/42.
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,
4/7 = 4 × 18/7 × 18 = 72/126 - Subtract the two like fractions:
147/126 - 72/126 = 147 - 72/126 = 75/126 - After reducing the fraction, the answer is 25/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18-4/7 21/18-8/7 21/36-4/7 21/18-4/14 63/18-4/7 21/18-12/7 21/54-4/7 21/18-4/21 21/18-20/7 21/90-4/7 21/18-4/35 21/18-28/7 21/18-4/49