Subtract 30/18 from 8/42
1st number: 8/42, 2nd number: 1 12/18
8/42 - 30/18 is -31/21.
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,
8/42 = 8 × 3/42 × 3 = 24/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
30/18 = 30 × 7/18 × 7 = 210/126 - Subtract the two like fractions:
24/126 - 210/126 = 24 - 210/126 = -186/126 - After reducing the fraction, the answer is -31/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/42-30/18 8/42-60/18 8/84-30/18 8/42-30/36 24/42-30/18 8/42-90/18 8/42-30/54 40/42-30/18 8/42-30/90 56/42-30/18