Subtract 28/21 from 35/90
1st number: 35/90, 2nd number: 1 7/21
35/90 - 28/21 is -17/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
35/90 = 35 × 7/90 × 7 = 245/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
28/21 = 28 × 30/21 × 30 = 840/630 - Subtract the two like fractions:
245/630 - 840/630 = 245 - 840/630 = -595/630 - After reducing the fraction, the answer is -17/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/90-28/21 35/90-56/21 35/90-28/42 35/90-84/21 35/90-28/63