Subtract 15/18 from 3/7
3/7 - 15/18 is -17/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 7 × 18 = 126,
3/7 = 3 × 18/7 × 18 = 54/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126 - Subtract the two like fractions:
54/126 - 105/126 = 54 - 105/126 = -51/126 - After reducing the fraction, the answer is -17/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/7-15/18 3/7-30/18 3/14-15/18 3/7-15/36 9/7-15/18 3/7-45/18 3/21-15/18 3/7-15/54 15/7-15/18 3/7-75/18 3/35-15/18 3/7-15/90 21/7-15/18 3/49-15/18