Subtract 12/21 from 30/60
30/60 - 12/21 is -1/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 60 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 60 × 7 = 420,
30/60 = 30 × 7/60 × 7 = 210/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
12/21 = 12 × 20/21 × 20 = 240/420 - Subtract the two like fractions:
210/420 - 240/420 = 210 - 240/420 = -30/420 - 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: 30/60-24/21 30/60-12/42 90/60-12/21 30/60-36/21 30/60-12/63 30/60-60/21 30/60-84/21