Subtract 20/80 from 28/72
28/72 - 20/80 is 5/36.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 80 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 72 × 10 = 720,
28/72 = 28 × 10/72 × 10 = 280/720 - Likewise, for the 2nd fraction, since 80 × 9 = 720,
20/80 = 20 × 9/80 × 9 = 180/720 - Subtract the two like fractions:
280/720 - 180/720 = 280 - 180/720 = 100/720 - After reducing the fraction, the answer is 5/36
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/72-20/80 28/72-40/80 84/72-20/80 28/72-60/80