Subtract 5/20 from 8/42
8/42 - 5/20 is -5/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
8/42 = 8 × 10/42 × 10 = 80/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
5/20 = 5 × 21/20 × 21 = 105/420 - Subtract the two like fractions:
80/420 - 105/420 = 80 - 105/420 = -25/420 - After reducing the fraction, the answer is -5/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/42-5/20 8/42-10/20 8/84-5/20 8/42-5/40 24/42-5/20 8/42-15/20 8/42-5/60 40/42-5/20 8/42-25/20 56/42-5/20 8/42-35/20