Subtract 90/21 from 1/18
1st number: 1/18, 2nd number: 4 6/21
1/18 - 90/21 is -533/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
1/18 = 1 × 7/18 × 7 = 7/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
90/21 = 90 × 6/21 × 6 = 540/126 - Subtract the two like fractions:
7/126 - 540/126 = 7 - 540/126 = -533/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/18-90/21 1/36-90/21 1/18-90/42 3/18-90/21 1/54-90/21 1/18-90/63 5/18-90/21 1/90-90/21 7/18-90/21