Subtract 4/48 from 21/42
21/42 - 4/48 is 5/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 48 is 336
Next, find the equivalent fraction of both fractional numbers with denominator 336 - For the 1st fraction, since 42 × 8 = 336,
21/42 = 21 × 8/42 × 8 = 168/336 - Likewise, for the 2nd fraction, since 48 × 7 = 336,
4/48 = 4 × 7/48 × 7 = 28/336 - Subtract the two like fractions:
168/336 - 28/336 = 168 - 28/336 = 140/336 - After reducing the fraction, the answer is 5/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42-8/48 21/84-4/48 21/42-4/96 63/42-4/48 21/42-12/48 21/42-20/48 21/42-28/48