Subtract 5/81 from 28/40
28/40 - 5/81 is 517/810.
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,
5/81 = 5 × 40/81 × 40 = 200/3240 - Subtract the two like fractions:
2268/3240 - 200/3240 = 2268 - 200/3240 = 2068/3240 - After reducing the fraction, the answer is 517/810
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40-5/81 28/40-10/81 28/80-5/81 84/40-5/81 28/40-15/81 28/40-25/81 28/40-35/81