Subtract 25/18 from 18/42
1st number: 18/42, 2nd number: 1 7/18
18/42 - 25/18 is -121/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
18/42 = 18 × 3/42 × 3 = 54/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
25/18 = 25 × 7/18 × 7 = 175/126 - Subtract the two like fractions:
54/126 - 175/126 = 54 - 175/126 = -121/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-25/18 18/42-50/18 18/84-25/18 18/42-25/36 54/42-25/18 18/42-75/18 18/42-25/54 90/42-25/18 18/42-25/90