Subtract 3/21 from 6/8
6/8 - 3/21 is 17/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
6/8 = 6 × 21/8 × 21 = 126/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
3/21 = 3 × 8/21 × 8 = 24/168 - Subtract the two like fractions:
126/168 - 24/168 = 126 - 24/168 = 102/168 - After reducing the fraction, the answer is 17/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 12/8-3/21 6/8-6/21 6/16-3/21 6/8-3/42 18/8-3/21 6/8-9/21 6/24-3/21 6/8-3/63 30/8-3/21 6/8-15/21 6/40-3/21 42/8-3/21 6/56-3/21