Subtract 56/90 from 7/21
7/21 - 56/90 is -13/45.
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,
7/21 = 7 × 30/21 × 30 = 210/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
56/90 = 56 × 7/90 × 7 = 392/630 - Subtract the two like fractions:
210/630 - 392/630 = 210 - 392/630 = -182/630 - After reducing the fraction, the answer is -13/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-56/90 7/42-56/90 7/63-56/90 35/21-56/90 49/21-56/90