Subtract 21/90 from 2/45
2/45 - 21/90 is -17/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 45 × 2 = 90,
2/45 = 2 × 2/45 × 2 = 4/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
21/90 = 21 × 1/90 × 1 = 21/90 - Subtract the two like fractions:
4/90 - 21/90 = 4 - 21/90 = -17/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/45-21/90 2/45-42/90 2/90-21/90 6/45-21/90 2/45-63/90 10/45-21/90 14/45-21/90