Subtract 56/70 from 20/42
20/42 - 56/70 is -34/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 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 70 × 3 = 210,
56/70 = 56 × 3/70 × 3 = 168/210 - Subtract the two like fractions:
100/210 - 168/210 = 100 - 168/210 = -68/210 - After reducing the fraction, the answer is -34/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-56/70 20/84-56/70 60/42-56/70