Subtract 81/72 from 1/42
1st number: 1/42, 2nd number: 1 9/72
1/42 - 81/72 is -185/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 42 × 12 = 504,
1/42 = 1 × 12/42 × 12 = 12/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
81/72 = 81 × 7/72 × 7 = 567/504 - Subtract the two like fractions:
12/504 - 567/504 = 12 - 567/504 = -555/504 - After reducing the fraction, the answer is -185/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/42-81/72 1/84-81/72 3/42-81/72 5/42-81/72 7/42-81/72