Subtract 1/21 from 42/18
1st number: 2 6/18, 2nd number: 1/21
42/18 - 1/21 is 16/7.
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,
42/18 = 42 × 7/18 × 7 = 294/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
1/21 = 1 × 6/21 × 6 = 6/126 - Subtract the two like fractions:
294/126 - 6/126 = 294 - 6/126 = 288/126 - After reducing the fraction, the answer is 16/7
- In mixed form: 22/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/18-1/21 42/18-2/21 42/36-1/21 42/18-1/42 42/18-3/21 42/54-1/21 42/18-1/63 42/18-5/21 42/90-1/21 42/18-7/21