Subtract 30/8 from 21/30
1st number: 21/30, 2nd number: 3 6/8
21/30 - 30/8 is -61/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 8 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
21/30 = 21 × 4/30 × 4 = 84/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
30/8 = 30 × 15/8 × 15 = 450/120 - Subtract the two like fractions:
84/120 - 450/120 = 84 - 450/120 = -366/120 - After reducing the fraction, the answer is -61/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-30/8 21/30-60/8 21/60-30/8 21/30-30/16 63/30-30/8 21/30-90/8 21/90-30/8 21/30-30/24 21/30-30/40 21/30-30/56