Subtract 15/18 from 20/72
20/72 - 15/18 is -5/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 18 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 72 × 1 = 72,
20/72 = 20 × 1/72 × 1 = 20/72 - Likewise, for the 2nd fraction, since 18 × 4 = 72,
15/18 = 15 × 4/18 × 4 = 60/72 - Subtract the two like fractions:
20/72 - 60/72 = 20 - 60/72 = -40/72 - After reducing the fraction, the answer is -5/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/72-15/18 20/72-30/18 20/72-15/36 60/72-15/18 20/72-45/18 20/72-15/54 20/72-75/18 20/72-15/90