Subtract 7/21 from 30/20
1st number: 1 10/20, 2nd number: 7/21
30/20 - 7/21 is 7/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
30/20 = 30 × 21/20 × 21 = 630/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
7/21 = 7 × 20/21 × 20 = 140/420 - Subtract the two like fractions:
630/420 - 140/420 = 630 - 140/420 = 490/420 - After reducing the fraction, the answer is 7/6
- In mixed form: 11/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/20-7/21 30/20-14/21 30/40-7/21 30/20-7/42 90/20-7/21 30/60-7/21 30/20-7/63 30/20-35/21 30/20-49/21