Subtract 12/42 from 3/20
3/20 - 12/42 is -19/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
3/20 = 3 × 21/20 × 21 = 63/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
12/42 = 12 × 10/42 × 10 = 120/420 - Subtract the two like fractions:
63/420 - 120/420 = 63 - 120/420 = -57/420 - After reducing the fraction, the answer is -19/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/20-12/42 3/20-24/42 3/40-12/42 3/20-12/84 9/20-12/42 3/20-36/42 3/60-12/42 15/20-12/42 3/20-60/42 21/20-12/42 3/20-84/42