Subtract 21/9 from 20/72
1st number: 20/72, 2nd number: 2 3/9
20/72 - 21/9 is -37/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 9 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 72 × 1 = 72,
20/72 = 20 × 1/72 × 1 = 20/72 - Likewise, for the 2nd fraction, since 9 × 8 = 72,
21/9 = 21 × 8/9 × 8 = 168/72 - Subtract the two like fractions:
20/72 - 168/72 = 20 - 168/72 = -148/72 - After reducing the fraction, the answer is -37/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/72-21/9 20/72-42/9 20/72-21/18 60/72-21/9 20/72-63/9 20/72-21/27 20/72-21/45 20/72-21/63