Subtract 15/8 from 18/30
1st number: 18/30, 2nd number: 1 7/8
18/30 - 15/8 is -51/40.
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,
18/30 = 18 × 4/30 × 4 = 72/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
15/8 = 15 × 15/8 × 15 = 225/120 - Subtract the two like fractions:
72/120 - 225/120 = 72 - 225/120 = -153/120 - After reducing the fraction, the answer is -51/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/30-15/8 18/30-30/8 18/60-15/8 18/30-15/16 54/30-15/8 18/30-45/8 18/90-15/8 18/30-15/24 90/30-15/8 18/30-75/8 18/30-15/40 18/30-15/56