Subtract 21/20 from 30/18
1st number: 1 12/18, 2nd number: 1 1/20
30/18 - 21/20 is 37/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 18 × 10 = 180,
30/18 = 30 × 10/18 × 10 = 300/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
21/20 = 21 × 9/20 × 9 = 189/180 - Subtract the two like fractions:
300/180 - 189/180 = 300 - 189/180 = 111/180 - After reducing the fraction, the answer is 37/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/18-21/20 30/18-42/20 30/36-21/20 30/18-21/40 90/18-21/20 30/18-63/20 30/54-21/20 30/18-21/60 30/90-21/20