Subtract 45/28 from 12/21
1st number: 12/21, 2nd number: 1 17/28
12/21 - 45/28 is -29/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
12/21 = 12 × 4/21 × 4 = 48/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
45/28 = 45 × 3/28 × 3 = 135/84 - Subtract the two like fractions:
48/84 - 135/84 = 48 - 135/84 = -87/84 - After reducing the fraction, the answer is -29/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21-45/28 12/21-90/28 12/42-45/28 12/21-45/56 36/21-45/28 12/63-45/28 12/21-45/84 60/21-45/28 84/21-45/28