Subtract 21/70 from 2/81
2/81 - 21/70 is -223/810.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 70 is 5670
Next, find the equivalent fraction of both fractional numbers with denominator 5670 - For the 1st fraction, since 81 × 70 = 5670,
2/81 = 2 × 70/81 × 70 = 140/5670 - Likewise, for the 2nd fraction, since 70 × 81 = 5670,
21/70 = 21 × 81/70 × 81 = 1701/5670 - Subtract the two like fractions:
140/5670 - 1701/5670 = 140 - 1701/5670 = -1561/5670 - After reducing the fraction, the answer is -223/810
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/81-21/70 2/81-42/70 6/81-21/70 2/81-63/70 10/81-21/70 14/81-21/70