Subtract 72/18 from 54/21
1st number: 2 12/21, 2nd number: 4 0/18
54/21 - 72/18 is -10/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
54/21 = 54 × 6/21 × 6 = 324/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
72/18 = 72 × 7/18 × 7 = 504/126 - Subtract the two like fractions:
324/126 - 504/126 = 324 - 504/126 = -180/126 - After reducing the fraction, the answer is -10/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/42-72/18 54/21-72/36 54/63-72/18 54/21-72/54 54/21-72/90