Subtract 18/21 from 4/12
4/12 - 18/21 is -11/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
4/12 = 4 × 7/12 × 7 = 28/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
18/21 = 18 × 4/21 × 4 = 72/84 - Subtract the two like fractions:
28/84 - 72/84 = 28 - 72/84 = -44/84 - After reducing the fraction, the answer is -11/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/12-18/21 4/12-36/21 4/24-18/21 4/12-18/42 4/12-54/21 4/36-18/21 4/12-18/63 20/12-18/21 4/12-90/21 4/60-18/21 28/12-18/21 4/84-18/21