Subtract 18/20 from 9/28
9/28 - 18/20 is -81/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
9/28 = 9 × 5/28 × 5 = 45/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
18/20 = 18 × 7/20 × 7 = 126/140 - Subtract the two like fractions:
45/140 - 126/140 = 45 - 126/140 = -81/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/28-18/20 9/28-36/20 9/56-18/20 9/28-18/40 27/28-18/20 9/28-54/20 9/84-18/20 9/28-18/60 45/28-18/20 9/28-90/20 63/28-18/20