Subtract 81/8 from 25/42
1st number: 25/42, 2nd number: 10 1/8
25/42 - 81/8 is -1601/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
25/42 = 25 × 4/42 × 4 = 100/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
81/8 = 81 × 21/8 × 21 = 1701/168 - Subtract the two like fractions:
100/168 - 1701/168 = 100 - 1701/168 = -1601/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 50/42-81/8 25/84-81/8 25/42-81/16 75/42-81/8 25/42-81/24 25/42-81/40 25/42-81/56