Subtract 9/21 from 12/30
12/30 - 9/21 is -1/35.
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,
9/21 = 9 × 10/21 × 10 = 90/210 - Subtract the two like fractions:
84/210 - 90/210 = 84 - 90/210 = -6/210 - 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: 24/30-9/21 12/30-18/21 12/60-9/21 12/30-9/42 36/30-9/21 12/30-27/21 12/90-9/21 12/30-9/63 60/30-9/21 12/30-45/21 84/30-9/21 12/30-63/21