Subtract 4/81 from 15/40
15/40 - 4/81 is 211/648.
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,
15/40 = 15 × 81/40 × 81 = 1215/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
4/81 = 4 × 40/81 × 40 = 160/3240 - Subtract the two like fractions:
1215/3240 - 160/3240 = 1215 - 160/3240 = 1055/3240 - After reducing the fraction, the answer is 211/648
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/40-4/81 15/40-8/81 15/80-4/81 45/40-4/81 15/40-12/81 75/40-4/81 15/40-20/81 15/40-28/81