Subtract 20/8 from 30/18
1st number: 1 12/18, 2nd number: 2 4/8
30/18 - 20/8 is -5/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 8 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 18 × 4 = 72,
30/18 = 30 × 4/18 × 4 = 120/72 - Likewise, for the 2nd fraction, since 8 × 9 = 72,
20/8 = 20 × 9/8 × 9 = 180/72 - Subtract the two like fractions:
120/72 - 180/72 = 120 - 180/72 = -60/72 - After reducing the fraction, the answer is -5/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/18-20/8 30/18-40/8 30/36-20/8 30/18-20/16 90/18-20/8 30/18-60/8 30/54-20/8 30/18-20/24 30/90-20/8 30/18-20/40 30/18-20/56