Subtract 10/30 from 21/70
21/70 - 10/30 is -1/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
21/70 = 21 × 3/70 × 3 = 63/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
10/30 = 10 × 7/30 × 7 = 70/210 - Subtract the two like fractions:
63/210 - 70/210 = 63 - 70/210 = -7/210 - After reducing the fraction, the answer is -1/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70-10/30 21/70-20/30 21/70-10/60 63/70-10/30 21/70-10/90 21/70-50/30 21/70-70/30