Subtract 18/28 from 9/20
9/20 - 18/28 is -27/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 28 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
9/20 = 9 × 7/20 × 7 = 63/140 - Likewise, for the 2nd fraction, since 28 × 5 = 140,
18/28 = 18 × 5/28 × 5 = 90/140 - Subtract the two like fractions:
63/140 - 90/140 = 63 - 90/140 = -27/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/20-18/28 9/20-36/28 9/40-18/28 9/20-18/56 27/20-18/28 9/20-54/28 9/60-18/28 9/20-18/84 45/20-18/28 9/20-90/28 63/20-18/28