Subtract 7/18 from 12/21
12/21 - 7/18 is 23/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
12/21 = 12 × 6/21 × 6 = 72/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
7/18 = 7 × 7/18 × 7 = 49/126 - Subtract the two like fractions:
72/126 - 49/126 = 72 - 49/126 = 23/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21-7/18 12/21-14/18 12/42-7/18 12/21-7/36 36/21-7/18 12/21-21/18 12/63-7/18 12/21-7/54 60/21-7/18 12/21-35/18 12/21-7/90 84/21-7/18 12/21-49/18