Subtract 35/20 from 21/90
1st number: 21/90, 2nd number: 1 15/20
21/90 - 35/20 is -91/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
21/90 = 21 × 2/90 × 2 = 42/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
35/20 = 35 × 9/20 × 9 = 315/180 - Subtract the two like fractions:
42/180 - 315/180 = 42 - 315/180 = -273/180 - After reducing the fraction, the answer is -91/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/90-35/20 21/90-70/20 21/90-35/40 63/90-35/20 21/90-35/60