Subtract 21/7 from 45/21
1st number: 2 3/21, 2nd number: 3 0/7
45/21 - 21/7 is -6/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
45/21 = 45 × 1/21 × 1 = 45/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
21/7 = 21 × 3/7 × 3 = 63/21 - Subtract the two like fractions:
45/21 - 63/21 = 45 - 63/21 = -18/21 - After reducing the fraction, the answer is -6/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/21-21/7 45/21-42/7 45/42-21/7 45/21-21/14 45/21-63/7 45/63-21/7 45/21-21/35 45/21-21/49