Subtract 15/54 from 7/42
7/42 - 15/54 is -1/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 42 × 9 = 378,
7/42 = 7 × 9/42 × 9 = 63/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
15/54 = 15 × 7/54 × 7 = 105/378 - Subtract the two like fractions:
63/378 - 105/378 = 63 - 105/378 = -42/378 - After reducing the fraction, the answer is -1/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/42-15/54 7/42-30/54 7/84-15/54 21/42-15/54 7/42-45/54 35/42-15/54 7/42-75/54 49/42-15/54