Subtract 81/12 from 42/30
1st number: 1 12/30, 2nd number: 6 9/12
42/30 - 81/12 is -107/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 12 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 30 × 2 = 60,
42/30 = 42 × 2/30 × 2 = 84/60 - Likewise, for the 2nd fraction, since 12 × 5 = 60,
81/12 = 81 × 5/12 × 5 = 405/60 - Subtract the two like fractions:
84/60 - 405/60 = 84 - 405/60 = -321/60 - After reducing the fraction, the answer is -107/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/30-81/12 42/60-81/12 42/30-81/24 42/90-81/12 42/30-81/36 42/30-81/60 42/30-81/84