Subtract 20/27 from 30/42
30/42 - 20/27 is -5/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 27 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 42 × 9 = 378,
30/42 = 30 × 9/42 × 9 = 270/378 - Likewise, for the 2nd fraction, since 27 × 14 = 378,
20/27 = 20 × 14/27 × 14 = 280/378 - Subtract the two like fractions:
270/378 - 280/378 = 270 - 280/378 = -10/378 - After reducing the fraction, the answer is -5/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/42-20/27 30/42-40/27 30/84-20/27 30/42-20/54 90/42-20/27 30/42-60/27 30/42-20/81