Subtract 1/81 from 28/40
28/40 - 1/81 is 557/810.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
28/40 = 28 × 81/40 × 81 = 2268/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
1/81 = 1 × 40/81 × 40 = 40/3240 - Subtract the two like fractions:
2268/3240 - 40/3240 = 2268 - 40/3240 = 2228/3240 - After reducing the fraction, the answer is 557/810
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40-1/81 28/40-2/81 28/80-1/81 84/40-1/81 28/40-3/81 28/40-5/81 28/40-7/81