Subtract 10/21 from 10/30
10/30 - 10/21 is -1/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
10/30 = 10 × 7/30 × 7 = 70/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
10/21 = 10 × 10/21 × 10 = 100/210 - Subtract the two like fractions:
70/210 - 100/210 = 70 - 100/210 = -30/210 - After reducing the fraction, the answer is -1/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/30-10/21 10/30-20/21 10/60-10/21 10/30-10/42 10/30-30/21 10/90-10/21 10/30-10/63 50/30-10/21 10/30-50/21 70/30-10/21 10/30-70/21