Subtract 9/21 from 42/27
1st number: 1 15/27, 2nd number: 9/21
42/27 - 9/21 is 71/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 27 and 21 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 27 × 7 = 189,
42/27 = 42 × 7/27 × 7 = 294/189 - Likewise, for the 2nd fraction, since 21 × 9 = 189,
9/21 = 9 × 9/21 × 9 = 81/189 - Subtract the two like fractions:
294/189 - 81/189 = 294 - 81/189 = 213/189 - After reducing the fraction, the answer is 71/63
- In mixed form: 18/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/27-9/21 42/27-18/21 42/54-9/21 42/27-9/42 42/27-27/21 42/81-9/21 42/27-9/63 42/27-45/21 42/27-63/21