Subtract 20/12 from 42/70
1st number: 42/70, 2nd number: 1 8/12
42/70 - 20/12 is -16/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 12 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 70 × 6 = 420,
42/70 = 42 × 6/70 × 6 = 252/420 - Likewise, for the 2nd fraction, since 12 × 35 = 420,
20/12 = 20 × 35/12 × 35 = 700/420 - Subtract the two like fractions:
252/420 - 700/420 = 252 - 700/420 = -448/420 - After reducing the fraction, the answer is -16/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/70-20/12 42/70-40/12 42/70-20/24 42/70-60/12 42/70-20/36 42/70-20/60 42/70-20/84