Subtract 25/8 from 20/42
1st number: 20/42, 2nd number: 3 1/8
20/42 - 25/8 is -445/168.
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,
20/42 = 20 × 4/42 × 4 = 80/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
25/8 = 25 × 21/8 × 21 = 525/168 - Subtract the two like fractions:
80/168 - 525/168 = 80 - 525/168 = -445/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-25/8 20/42-50/8 20/84-25/8 20/42-25/16 60/42-25/8 20/42-75/8 20/42-25/24 20/42-25/40 20/42-25/56