Subtract 8/70 from 21/80
21/80 - 8/70 is 83/560.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 70 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 80 × 7 = 560,
21/80 = 21 × 7/80 × 7 = 147/560 - Likewise, for the 2nd fraction, since 70 × 8 = 560,
8/70 = 8 × 8/70 × 8 = 64/560 - Subtract the two like fractions:
147/560 - 64/560 = 147 - 64/560 = 83/560
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/80-8/70 21/80-16/70 63/80-8/70 21/80-24/70 21/80-40/70 21/80-56/70