Subtract 7/20 from 20/42
20/42 - 7/20 is 53/420.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
20/42 = 20 × 10/42 × 10 = 200/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420 - Subtract the two like fractions:
200/420 - 147/420 = 200 - 147/420 = 53/420
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-7/20 20/42-14/20 20/84-7/20 20/42-7/40 60/42-7/20 20/42-21/20 20/42-7/60 20/42-35/20 20/42-49/20