Subtract 30/27 from 18/42
1st number: 18/42, 2nd number: 1 3/27
18/42 - 30/27 is -43/63.
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,
18/42 = 18 × 9/42 × 9 = 162/378 - Likewise, for the 2nd fraction, since 27 × 14 = 378,
30/27 = 30 × 14/27 × 14 = 420/378 - Subtract the two like fractions:
162/378 - 420/378 = 162 - 420/378 = -258/378 - After reducing the fraction, the answer is -43/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-30/27 18/42-60/27 18/84-30/27 18/42-30/54 54/42-30/27 18/42-90/27 18/42-30/81 90/42-30/27