Subtract 18/28 from 18/72
18/72 - 18/28 is -11/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 28 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
18/72 = 18 × 7/72 × 7 = 126/504 - Likewise, for the 2nd fraction, since 28 × 18 = 504,
18/28 = 18 × 18/28 × 18 = 324/504 - Subtract the two like fractions:
126/504 - 324/504 = 126 - 324/504 = -198/504 - After reducing the fraction, the answer is -11/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/72-18/28 18/72-36/28 18/72-18/56 54/72-18/28 18/72-54/28 18/72-18/84 90/72-18/28 18/72-90/28