Subtract 30/54 from 18/21
18/21 - 30/54 is 19/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
18/21 = 18 × 18/21 × 18 = 324/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
30/54 = 30 × 7/54 × 7 = 210/378 - Subtract the two like fractions:
324/378 - 210/378 = 324 - 210/378 = 114/378 - 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: 36/21-30/54 18/21-60/54 18/42-30/54 54/21-30/54 18/21-90/54 18/63-30/54 90/21-30/54