Subtract 90/28 from 42/84
1st number: 42/84, 2nd number: 3 6/28
42/84 - 90/28 is -19/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 84 × 1 = 84,
42/84 = 42 × 1/84 × 1 = 42/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
90/28 = 90 × 3/28 × 3 = 270/84 - Subtract the two like fractions:
42/84 - 270/84 = 42 - 270/84 = -228/84 - After reducing the fraction, the answer is -19/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84-90/56 42/84-90/84