Subtract 20/49 from 18/42
18/42 - 20/49 is 1/49.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 49 is 294
Next, find the equivalent fraction of both fractional numbers with denominator 294 - For the 1st fraction, since 42 × 7 = 294,
18/42 = 18 × 7/42 × 7 = 126/294 - Likewise, for the 2nd fraction, since 49 × 6 = 294,
20/49 = 20 × 6/49 × 6 = 120/294 - Subtract the two like fractions:
126/294 - 120/294 = 126 - 120/294 = 6/294 - After reducing the fraction, the answer is 1/49
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-20/49 18/42-40/49 18/84-20/49 18/42-20/98 54/42-20/49 18/42-60/49 90/42-20/49