Subtract 42/21 from 20/35
1st number: 20/35, 2nd number: 2 0/21
20/35 - 42/21 is -10/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 35 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 35 × 3 = 105,
20/35 = 20 × 3/35 × 3 = 60/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
42/21 = 42 × 5/21 × 5 = 210/105 - Subtract the two like fractions:
60/105 - 210/105 = 60 - 210/105 = -150/105 - After reducing the fraction, the answer is -10/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/35-42/21 20/35-84/21 20/70-42/21 60/35-42/21 20/35-42/63