Subtract 84/21 from 3/8
1st number: 3/8, 2nd number: 4 0/21
3/8 - 84/21 is -29/8.
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,
3/8 = 3 × 21/8 × 21 = 63/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
84/21 = 84 × 8/21 × 8 = 672/168 - Subtract the two like fractions:
63/168 - 672/168 = 63 - 672/168 = -609/168 - After reducing the fraction, the answer is -29/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/8-84/21 3/16-84/21 3/8-84/42 9/8-84/21 3/24-84/21 3/8-84/63 15/8-84/21 3/40-84/21 21/8-84/21 3/56-84/21