Subtract 81/7 from 45/42
1st number: 1 3/42, 2nd number: 11 4/7
45/42 - 81/7 is -21/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 7 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
45/42 = 45 × 1/42 × 1 = 45/42 - Likewise, for the 2nd fraction, since 7 × 6 = 42,
81/7 = 81 × 6/7 × 6 = 486/42 - Subtract the two like fractions:
45/42 - 486/42 = 45 - 486/42 = -441/42 - After reducing the fraction, the answer is -21/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/42-81/7 45/84-81/7 45/42-81/14 45/42-81/21 45/42-81/35 45/42-81/49