Subtract 20/8 from 18/9
1st number: 2 0/9, 2nd number: 2 4/8
18/9 - 20/8 is -1/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 8 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 9 × 8 = 72,
18/9 = 18 × 8/9 × 8 = 144/72 - Likewise, for the 2nd fraction, since 8 × 9 = 72,
20/8 = 20 × 9/8 × 9 = 180/72 - Subtract the two like fractions:
144/72 - 180/72 = 144 - 180/72 = -36/72 - After reducing the fraction, the answer is -1/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/9-20/8 18/9-40/8 18/9-20/16 54/9-20/8 18/9-60/8 18/27-20/8 18/9-20/24 90/9-20/8 18/45-20/8 18/9-20/40 18/63-20/8 18/9-20/56