Subtract 48/81 from 21/72
21/72 - 48/81 is -65/216.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 81 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 72 × 9 = 648,
21/72 = 21 × 9/72 × 9 = 189/648 - Likewise, for the 2nd fraction, since 81 × 8 = 648,
48/81 = 48 × 8/81 × 8 = 384/648 - Subtract the two like fractions:
189/648 - 384/648 = 189 - 384/648 = -195/648 - After reducing the fraction, the answer is -65/216
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/72-48/81 21/72-96/81 63/72-48/81