Subtract 90/10 from 21/20
1st number: 1 1/20, 2nd number: 9 0/10
21/20 - 90/10 is -159/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 10 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 20 × 1 = 20,
21/20 = 21 × 1/20 × 1 = 21/20 - Likewise, for the 2nd fraction, since 10 × 2 = 20,
90/10 = 90 × 2/10 × 2 = 180/20 - Subtract the two like fractions:
21/20 - 180/20 = 21 - 180/20 = -159/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20-90/10 21/40-90/10 21/20-90/20 63/20-90/10 21/60-90/10 21/20-90/30 21/20-90/50 21/20-90/70