Subtract 12/42 from 21/8
1st number: 2 5/8, 2nd number: 12/42
21/8 - 12/42 is 131/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 42 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
21/8 = 21 × 21/8 × 21 = 441/168 - Likewise, for the 2nd fraction, since 42 × 4 = 168,
12/42 = 12 × 4/42 × 4 = 48/168 - Subtract the two like fractions:
441/168 - 48/168 = 441 - 48/168 = 393/168 - After reducing the fraction, the answer is 131/56
- In mixed form: 219/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/8-12/42 21/8-24/42 21/16-12/42 21/8-12/84 63/8-12/42 21/8-36/42 21/24-12/42 21/8-60/42 21/40-12/42 21/8-84/42 21/56-12/42