Subtract 81/28 from 42/90
1st number: 42/90, 2nd number: 2 25/28
42/90 - 81/28 is -1019/420.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 28 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 90 × 14 = 1260,
42/90 = 42 × 14/90 × 14 = 588/1260 - Likewise, for the 2nd fraction, since 28 × 45 = 1260,
81/28 = 81 × 45/28 × 45 = 3645/1260 - Subtract the two like fractions:
588/1260 - 3645/1260 = 588 - 3645/1260 = -3057/1260 - After reducing the fraction, the answer is -1019/420
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/90-81/28 42/90-81/56 42/90-81/84