Subtract 12/45 from 5/21
5/21 - 12/45 is -1/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
5/21 = 5 × 15/21 × 15 = 75/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
12/45 = 12 × 7/45 × 7 = 84/315 - Subtract the two like fractions:
75/315 - 84/315 = 75 - 84/315 = -9/315 - After reducing the fraction, the answer is -1/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/21-12/45 5/21-24/45 5/42-12/45 5/21-12/90 15/21-12/45 5/21-36/45 5/63-12/45 25/21-12/45 5/21-60/45 35/21-12/45 5/21-84/45