Subtract 8/21 from 21/30
21/30 - 8/21 is 67/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
8/21 = 8 × 10/21 × 10 = 80/210 - Subtract the two like fractions:
147/210 - 80/210 = 147 - 80/210 = 67/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-8/21 21/30-16/21 21/60-8/21 21/30-8/42 63/30-8/21 21/30-24/21 21/90-8/21 21/30-8/63 21/30-40/21 21/30-56/21