Subtract 9/20 from 9/28
9/28 - 9/20 is -9/70.
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,
9/20 = 9 × 7/20 × 7 = 63/140 - Subtract the two like fractions:
45/140 - 63/140 = 45 - 63/140 = -18/140 - After reducing the fraction, the answer is -9/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/28-9/20 9/28-18/20 9/56-9/20 9/28-9/40 27/28-9/20 9/28-27/20 9/84-9/20 9/28-9/60 45/28-9/20 9/28-45/20 63/28-9/20 9/28-63/20