Subtract 12/30 from 18/21
18/21 - 12/30 is 16/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
18/21 = 18 × 10/21 × 10 = 180/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
12/30 = 12 × 7/30 × 7 = 84/210 - Subtract the two like fractions:
180/210 - 84/210 = 180 - 84/210 = 96/210 - After reducing the fraction, the answer is 16/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21-12/30 18/21-24/30 18/42-12/30 18/21-12/60 54/21-12/30 18/21-36/30 18/63-12/30 18/21-12/90 90/21-12/30 18/21-60/30 18/21-84/30