Subtract 21/30 from 5/7
5/7 - 21/30 is 1/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 7 × 30 = 210,
5/7 = 5 × 30/7 × 30 = 150/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Subtract the two like fractions:
150/210 - 147/210 = 150 - 147/210 = 3/210 - After reducing the fraction, the answer is 1/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/7-21/30 5/7-42/30 5/14-21/30 5/7-21/60 15/7-21/30 5/7-63/30 5/21-21/30 5/7-21/90 25/7-21/30 5/35-21/30 35/7-21/30 5/49-21/30