Subtract 28/21 from 20/25
1st number: 20/25, 2nd number: 1 7/21
20/25 - 28/21 is -8/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 25 and 21 is 525
Next, find the equivalent fraction of both fractional numbers with denominator 525 - For the 1st fraction, since 25 × 21 = 525,
20/25 = 20 × 21/25 × 21 = 420/525 - Likewise, for the 2nd fraction, since 21 × 25 = 525,
28/21 = 28 × 25/21 × 25 = 700/525 - Subtract the two like fractions:
420/525 - 700/525 = 420 - 700/525 = -280/525 - After reducing the fraction, the answer is -8/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/25-28/21 20/25-56/21 20/50-28/21 20/25-28/42 60/25-28/21 20/25-84/21 20/75-28/21 20/25-28/63