Subtract 72/90 from 35/21
1st number: 1 14/21, 2nd number: 72/90
35/21 - 72/90 is 13/15.
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,
35/21 = 35 × 30/21 × 30 = 1050/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
72/90 = 72 × 7/90 × 7 = 504/630 - Subtract the two like fractions:
1050/630 - 504/630 = 1050 - 504/630 = 546/630 - After reducing the fraction, the answer is 13/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/21-72/90 35/42-72/90 35/63-72/90