Subtract 21/7 from 90/18
1st number: 5 0/18, 2nd number: 3 0/7
90/18 - 21/7 is 2/1.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
90/18 = 90 × 7/18 × 7 = 630/126 - Likewise, for the 2nd fraction, since 7 × 18 = 126,
21/7 = 21 × 18/7 × 18 = 378/126 - Subtract the two like fractions:
630/126 - 378/126 = 630 - 378/126 = 252/126 - After reducing the fraction, the answer is 2/1
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/18-42/7 90/36-21/7 90/18-21/14 90/18-63/7 90/54-21/7 90/18-21/35 90/18-21/49