Subtract 1/20 from 3/81
3/81 - 1/20 is -7/540.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 20 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 81 × 20 = 1620,
3/81 = 3 × 20/81 × 20 = 60/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
1/20 = 1 × 81/20 × 81 = 81/1620 - Subtract the two like fractions:
60/1620 - 81/1620 = 60 - 81/1620 = -21/1620 - After reducing the fraction, the answer is -7/540
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/81-1/20 3/81-2/20 3/81-1/40 9/81-1/20 3/81-3/20 3/81-1/60 15/81-1/20 3/81-5/20 21/81-1/20 3/81-7/20