Subtract 72/21 from 45/8
1st number: 5 5/8, 2nd number: 3 9/21
45/8 - 72/21 is 123/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
45/8 = 45 × 21/8 × 21 = 945/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
72/21 = 72 × 8/21 × 8 = 576/168 - Subtract the two like fractions:
945/168 - 576/168 = 945 - 576/168 = 369/168 - After reducing the fraction, the answer is 123/56
- In mixed form: 211/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/8-72/21 45/16-72/21 45/8-72/42 45/24-72/21 45/8-72/63 45/40-72/21 45/56-72/21