Subtract 3/42 from 15/18
15/18 - 3/42 is 16/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 42 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126 - Likewise, for the 2nd fraction, since 42 × 3 = 126,
3/42 = 3 × 3/42 × 3 = 9/126 - Subtract the two like fractions:
105/126 - 9/126 = 105 - 9/126 = 96/126 - After reducing the fraction, the answer is 16/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/18-3/42 15/18-6/42 15/36-3/42 15/18-3/84 45/18-3/42 15/18-9/42 15/54-3/42 75/18-3/42 15/18-15/42 15/90-3/42 15/18-21/42