Subtract 21/50 from 10/90
10/90 - 21/50 is -139/450.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 50 is 450
Next, find the equivalent fraction of both fractional numbers with denominator 450 - For the 1st fraction, since 90 × 5 = 450,
10/90 = 10 × 5/90 × 5 = 50/450 - Likewise, for the 2nd fraction, since 50 × 9 = 450,
21/50 = 21 × 9/50 × 9 = 189/450 - Subtract the two like fractions:
50/450 - 189/450 = 50 - 189/450 = -139/450
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/90-21/50 10/90-42/50 30/90-21/50 10/90-63/50 50/90-21/50 70/90-21/50