Subtract 81/28 from 42/18
1st number: 2 6/18, 2nd number: 2 25/28
42/18 - 81/28 is -47/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 28 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 18 × 14 = 252,
42/18 = 42 × 14/18 × 14 = 588/252 - Likewise, for the 2nd fraction, since 28 × 9 = 252,
81/28 = 81 × 9/28 × 9 = 729/252 - Subtract the two like fractions:
588/252 - 729/252 = 588 - 729/252 = -141/252 - After reducing the fraction, the answer is -47/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/18-81/28 42/36-81/28 42/18-81/56 42/54-81/28 42/18-81/84 42/90-81/28