Subtract 21/72 from 90/18
1st number: 5 0/18, 2nd number: 21/72
90/18 - 21/72 is 113/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 72 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 18 × 4 = 72,
90/18 = 90 × 4/18 × 4 = 360/72 - Likewise, for the 2nd fraction, since 72 × 1 = 72,
21/72 = 21 × 1/72 × 1 = 21/72 - Subtract the two like fractions:
360/72 - 21/72 = 360 - 21/72 = 339/72 - After reducing the fraction, the answer is 113/24
- In mixed form: 417/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/18-42/72 90/36-21/72 90/18-63/72 90/54-21/72