Subtract 4/90 from 5/21
5/21 - 4/90 is 61/315.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
5/21 = 5 × 30/21 × 30 = 150/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
4/90 = 4 × 7/90 × 7 = 28/630 - Subtract the two like fractions:
150/630 - 28/630 = 150 - 28/630 = 122/630 - After reducing the fraction, the answer is 61/315
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/21-4/90 5/21-8/90 5/42-4/90 15/21-4/90 5/21-12/90 5/63-4/90 25/21-4/90 5/21-20/90 35/21-4/90 5/21-28/90