Subtract 18/5 from 21/30
1st number: 21/30, 2nd number: 3 3/5
21/30 - 18/5 is -29/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 5 is 30
Next, find the equivalent fraction of both fractional numbers with denominator 30 - For the 1st fraction, since 30 × 1 = 30,
21/30 = 21 × 1/30 × 1 = 21/30 - Likewise, for the 2nd fraction, since 5 × 6 = 30,
18/5 = 18 × 6/5 × 6 = 108/30 - Subtract the two like fractions:
21/30 - 108/30 = 21 - 108/30 = -87/30 - After reducing the fraction, the answer is -29/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-18/5 21/30-36/5 21/60-18/5 21/30-18/10 63/30-18/5 21/30-54/5 21/90-18/5 21/30-18/15 21/30-90/5 21/30-18/25 21/30-18/35