Subtract 20/12 from 45/28
1st number: 1 17/28, 2nd number: 1 8/12
45/28 - 20/12 is -5/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
45/28 = 45 × 3/28 × 3 = 135/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
20/12 = 20 × 7/12 × 7 = 140/84 - Subtract the two like fractions:
135/84 - 140/84 = 135 - 140/84 = -5/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/28-20/12 45/28-40/12 45/56-20/12 45/28-20/24 45/28-60/12 45/84-20/12 45/28-20/36 45/28-20/60 45/28-20/84