Subtract 30/27 from 21/7
1st number: 3 0/7, 2nd number: 1 3/27
21/7 - 30/27 is 17/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 27 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 7 × 27 = 189,
21/7 = 21 × 27/7 × 27 = 567/189 - Likewise, for the 2nd fraction, since 27 × 7 = 189,
30/27 = 30 × 7/27 × 7 = 210/189 - Subtract the two like fractions:
567/189 - 210/189 = 567 - 210/189 = 357/189 - After reducing the fraction, the answer is 17/9
- In mixed form: 18/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/7-30/27 21/7-60/27 21/14-30/27 21/7-30/54 63/7-30/27 21/7-90/27 21/7-30/81 21/35-30/27 21/49-30/27