Subtract 12/21 from 15/30
15/30 - 12/21 is -1/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
15/30 = 15 × 7/30 × 7 = 105/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
12/21 = 12 × 10/21 × 10 = 120/210 - Subtract the two like fractions:
105/210 - 120/210 = 105 - 120/210 = -15/210 - After reducing the fraction, the answer is -1/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 15/30-24/21 15/60-12/21 15/30-12/42 45/30-12/21 15/30-36/21 15/90-12/21 15/30-12/63 75/30-12/21 15/30-60/21 15/30-84/21