Subtract 63/21 from 7/9
1st number: 7/9, 2nd number: 3 0/21
7/9 - 63/21 is -20/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
7/9 = 7 × 7/9 × 7 = 49/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
63/21 = 63 × 3/21 × 3 = 189/63 - Subtract the two like fractions:
49/63 - 189/63 = 49 - 189/63 = -140/63 - After reducing the fraction, the answer is -20/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/9-63/21 7/18-63/21 7/9-63/42 21/9-63/21 7/27-63/21 35/9-63/21 7/45-63/21 49/9-63/21 7/63-63/21