Subtract 20/21 from 1/9
1/9 - 20/21 is -53/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
1/9 = 1 × 7/9 × 7 = 7/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
20/21 = 20 × 3/21 × 3 = 60/63 - Subtract the two like fractions:
7/63 - 60/63 = 7 - 60/63 = -53/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/9-20/21 1/9-40/21 1/18-20/21 1/9-20/42 3/9-20/21 1/9-60/21 1/27-20/21 1/9-20/63 5/9-20/21 1/45-20/21 7/9-20/21 1/63-20/21