Subtract 64/9 from 18/21
1st number: 18/21, 2nd number: 7 1/9
18/21 - 64/9 is -394/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
18/21 = 18 × 3/21 × 3 = 54/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
64/9 = 64 × 7/9 × 7 = 448/63 - Subtract the two like fractions:
54/63 - 448/63 = 54 - 448/63 = -394/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21-64/9 18/42-64/9 18/21-64/18 54/21-64/9 18/63-64/9 18/21-64/27 90/21-64/9 18/21-64/45 18/21-64/63