Subtract 3/4 from 12/21
12/21 - 3/4 is -5/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 4 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 4 × 21 = 84,
3/4 = 3 × 21/4 × 21 = 63/84 - Subtract the two like fractions:
48/84 - 63/84 = 48 - 63/84 = -15/84 - After reducing the fraction, the answer is -5/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21-3/4 12/21-6/4 12/42-3/4 12/21-3/8 36/21-3/4 12/21-9/4 12/63-3/4 12/21-3/12 60/21-3/4 12/21-15/4 12/21-3/20 84/21-3/4 12/21-21/4 12/21-3/28