Subtract 27/7 from 20/42
1st number: 20/42, 2nd number: 3 6/7
20/42 - 27/7 is -71/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 7 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
20/42 = 20 × 1/42 × 1 = 20/42 - Likewise, for the 2nd fraction, since 7 × 6 = 42,
27/7 = 27 × 6/7 × 6 = 162/42 - Subtract the two like fractions:
20/42 - 162/42 = 20 - 162/42 = -142/42 - After reducing the fraction, the answer is -71/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-27/7 20/42-54/7 20/84-27/7 20/42-27/14 60/42-27/7 20/42-81/7 20/42-27/21 20/42-27/35 20/42-27/49