Subtract 12/30 from 20/42
20/42 - 12/30 is 8/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
20/42 = 20 × 5/42 × 5 = 100/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
12/30 = 12 × 7/30 × 7 = 84/210 - Subtract the two like fractions:
100/210 - 84/210 = 100 - 84/210 = 16/210 - After reducing the fraction, the answer is 8/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-12/30 20/42-24/30 20/84-12/30 20/42-12/60 60/42-12/30 20/42-36/30 20/42-12/90 20/42-60/30 20/42-84/30