Subtract 21/18 from 18/63
1st number: 18/63, 2nd number: 1 3/18
18/63 - 21/18 is -37/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 63 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 63 × 2 = 126,
18/63 = 18 × 2/63 × 2 = 36/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Subtract the two like fractions:
36/126 - 147/126 = 36 - 147/126 = -111/126 - After reducing the fraction, the answer is -37/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/63-21/18 18/63-42/18 18/63-21/36 54/63-21/18 18/63-63/18 18/63-21/54 90/63-21/18 18/63-21/90