Subtract 12/21 from 20/30
20/30 - 12/21 is 2/21.
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,
20/30 = 20 × 7/30 × 7 = 140/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
12/21 = 12 × 10/21 × 10 = 120/210 - Subtract the two like fractions:
140/210 - 120/210 = 140 - 120/210 = 20/210 - After reducing the fraction, the answer is 2/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/30-12/21 20/30-24/21 20/60-12/21 20/30-12/42 60/30-12/21 20/30-36/21 20/90-12/21 20/30-12/63 20/30-60/21 20/30-84/21