Subtract 42/7 from 81/4
1st number: 20 1/4, 2nd number: 6 0/7
81/4 - 42/7 is 57/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 7 is 28
Next, find the equivalent fraction of both fractional numbers with denominator 28 - For the 1st fraction, since 4 × 7 = 28,
81/4 = 81 × 7/4 × 7 = 567/28 - Likewise, for the 2nd fraction, since 7 × 4 = 28,
42/7 = 42 × 4/7 × 4 = 168/28 - Subtract the two like fractions:
567/28 - 168/28 = 567 - 168/28 = 399/28 - After reducing the fraction, the answer is 57/4
- In mixed form: 141/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/4-84/7 81/8-42/7 81/4-42/14 81/12-42/7 81/4-42/21 81/20-42/7 81/4-42/35 81/28-42/7 81/4-42/49