Subtract 7/20 from 42/21
1st number: 2 0/21, 2nd number: 7/20
42/21 - 7/20 is 33/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
42/21 = 42 × 20/21 × 20 = 840/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420 - Subtract the two like fractions:
840/420 - 147/420 = 840 - 147/420 = 693/420 - After reducing the fraction, the answer is 33/20
- In mixed form: 113/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21-7/20 42/21-14/20 42/21-7/40 42/21-21/20 42/63-7/20 42/21-7/60 42/21-35/20 42/21-49/20