Subtract 84/27 from 42/21
1st number: 2 0/21, 2nd number: 3 3/27
42/21 - 84/27 is -10/9.
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,
42/21 = 42 × 9/21 × 9 = 378/189 - Likewise, for the 2nd fraction, since 27 × 7 = 189,
84/27 = 84 × 7/27 × 7 = 588/189 - Subtract the two like fractions:
378/189 - 588/189 = 378 - 588/189 = -210/189 - After reducing the fraction, the answer is -10/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21-84/27 42/21-84/54 42/63-84/27 42/21-84/81