Subtract 21/40 from 3/80
3/80 - 21/40 is -39/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 40 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 80 × 1 = 80,
3/80 = 3 × 1/80 × 1 = 3/80 - Likewise, for the 2nd fraction, since 40 × 2 = 80,
21/40 = 21 × 2/40 × 2 = 42/80 - Subtract the two like fractions:
3/80 - 42/80 = 3 - 42/80 = -39/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/80-21/40 3/80-42/40 3/80-21/80 9/80-21/40 3/80-63/40 15/80-21/40 21/80-21/40