Subtract 21/80 from 3/20
3/20 - 21/80 is -9/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 80 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 20 × 4 = 80,
3/20 = 3 × 4/20 × 4 = 12/80 - Likewise, for the 2nd fraction, since 80 × 1 = 80,
21/80 = 21 × 1/80 × 1 = 21/80 - Subtract the two like fractions:
12/80 - 21/80 = 12 - 21/80 = -9/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/20-21/80 3/20-42/80 3/40-21/80 9/20-21/80 3/20-63/80 3/60-21/80 15/20-21/80 21/20-21/80