Subtract 9/21 from 2/8
2/8 - 9/21 is -5/28.
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,
2/8 = 2 × 21/8 × 21 = 42/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
9/21 = 9 × 8/21 × 8 = 72/168 - Subtract the two like fractions:
42/168 - 72/168 = 42 - 72/168 = -30/168 - After reducing the fraction, the answer is -5/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/8-9/21 2/8-18/21 2/16-9/21 2/8-9/42 6/8-9/21 2/8-27/21 2/24-9/21 2/8-9/63 10/8-9/21 2/8-45/21 2/40-9/21 14/8-9/21 2/8-63/21 2/56-9/21