Subtract 84/70 from 21/30
1st number: 21/30, 2nd number: 1 14/70
21/30 - 84/70 is -1/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
84/70 = 84 × 3/70 × 3 = 252/210 - Subtract the two like fractions:
147/210 - 252/210 = 147 - 252/210 = -105/210 - After reducing the fraction, the answer is -1/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-84/70 21/60-84/70 63/30-84/70 21/90-84/70