Subtract 10/21 from 12/28
12/28 - 10/21 is -1/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
12/28 = 12 × 3/28 × 3 = 36/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
10/21 = 10 × 4/21 × 4 = 40/84 - Subtract the two like fractions:
36/84 - 40/84 = 36 - 40/84 = -4/84 - After reducing the fraction, the answer is -1/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/28-10/21 12/28-20/21 12/56-10/21 12/28-10/42 36/28-10/21 12/28-30/21 12/84-10/21 12/28-10/63 60/28-10/21 12/28-50/21 84/28-10/21 12/28-70/21