Subtract 12/27 from 3/21
3/21 - 12/27 is -19/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 21 × 9 = 189,
3/21 = 3 × 9/21 × 9 = 27/189 - Likewise, for the 2nd fraction, since 27 × 7 = 189,
12/27 = 12 × 7/27 × 7 = 84/189 - Subtract the two like fractions:
27/189 - 84/189 = 27 - 84/189 = -57/189 - After reducing the fraction, the answer is -19/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21-12/27 3/21-24/27 3/42-12/27 3/21-12/54 9/21-12/27 3/21-36/27 3/63-12/27 3/21-12/81 15/21-12/27 3/21-60/27 3/21-84/27