Subtract 15/21 from 12/30
12/30 - 15/21 is -11/35.
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,
12/30 = 12 × 7/30 × 7 = 84/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
15/21 = 15 × 10/21 × 10 = 150/210 - Subtract the two like fractions:
84/210 - 150/210 = 84 - 150/210 = -66/210 - After reducing the fraction, the answer is -11/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/30-15/21 12/30-30/21 12/60-15/21 12/30-15/42 36/30-15/21 12/30-45/21 12/90-15/21 12/30-15/63 60/30-15/21 12/30-75/21 84/30-15/21