Subtract 18/42 from 8/12
8/12 - 18/42 is 5/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
8/12 = 8 × 7/12 × 7 = 56/84 - Likewise, for the 2nd fraction, since 42 × 2 = 84,
18/42 = 18 × 2/42 × 2 = 36/84 - Subtract the two like fractions:
56/84 - 36/84 = 56 - 36/84 = 20/84 - After reducing the fraction, the answer is 5/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/12-18/42 8/12-36/42 8/24-18/42 8/12-18/84 24/12-18/42 8/12-54/42 8/36-18/42 40/12-18/42 8/12-90/42 8/60-18/42 56/12-18/42 8/84-18/42