Subtract 70/12 from 21/30
1st number: 21/30, 2nd number: 5 10/12
21/30 - 70/12 is -77/15.
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,
21/30 = 21 × 2/30 × 2 = 42/60 - Likewise, for the 2nd fraction, since 12 × 5 = 60,
70/12 = 70 × 5/12 × 5 = 350/60 - Subtract the two like fractions:
42/60 - 350/60 = 42 - 350/60 = -308/60 - After reducing the fraction, the answer is -77/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-70/12 21/60-70/12 21/30-70/24 63/30-70/12 21/90-70/12 21/30-70/36 21/30-70/60 21/30-70/84