Subtract 4/5 from 21/80
21/80 - 4/5 is -43/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 5 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 80 × 1 = 80,
21/80 = 21 × 1/80 × 1 = 21/80 - Likewise, for the 2nd fraction, since 5 × 16 = 80,
4/5 = 4 × 16/5 × 16 = 64/80 - Subtract the two like fractions:
21/80 - 64/80 = 21 - 64/80 = -43/80
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/80-4/5 21/80-8/5 21/80-4/10 63/80-4/5 21/80-12/5 21/80-4/15 21/80-20/5 21/80-4/25 21/80-28/5 21/80-4/35