Subtract 20/18 from 21/2
1st number: 10 1/2, 2nd number: 1 2/18
21/2 - 20/18 is 169/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 18 is 18
Next, find the equivalent fraction of both fractional numbers with denominator 18 - For the 1st fraction, since 2 × 9 = 18,
21/2 = 21 × 9/2 × 9 = 189/18 - Likewise, for the 2nd fraction, since 18 × 1 = 18,
20/18 = 20 × 1/18 × 1 = 20/18 - Subtract the two like fractions:
189/18 - 20/18 = 189 - 20/18 = 169/18 - In mixed form: 97/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/2-20/18 21/2-40/18 21/4-20/18 21/2-20/36 63/2-20/18 21/2-60/18 21/6-20/18 21/2-20/54 21/10-20/18 21/2-20/90 21/14-20/18