Subtract 30/10 from 7/21
1st number: 7/21, 2nd number: 3 0/10
7/21 - 30/10 is -8/3.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 10 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
7/21 = 7 × 10/21 × 10 = 70/210 - Likewise, for the 2nd fraction, since 10 × 21 = 210,
30/10 = 30 × 21/10 × 21 = 630/210 - Subtract the two like fractions:
70/210 - 630/210 = 70 - 630/210 = -560/210 - After reducing the fraction, the answer is -8/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-30/10 7/21-60/10 7/42-30/10 7/21-30/20 7/21-90/10 7/63-30/10 35/21-30/10 7/21-30/50 49/21-30/10 7/21-30/70