Subtract 18/4 from 15/21
1st number: 15/21, 2nd number: 4 2/4
15/21 - 18/4 is -53/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 4 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Likewise, for the 2nd fraction, since 4 × 21 = 84,
18/4 = 18 × 21/4 × 21 = 378/84 - Subtract the two like fractions:
60/84 - 378/84 = 60 - 378/84 = -318/84 - After reducing the fraction, the answer is -53/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21-18/4 15/21-36/4 15/42-18/4 15/21-18/8 45/21-18/4 15/21-54/4 15/63-18/4 15/21-18/12 75/21-18/4 15/21-90/4 15/21-18/20 15/21-18/28