Subtract 5/20 from 4/90
4/90 - 5/20 is -37/180.
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,
4/90 = 4 × 2/90 × 2 = 8/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
5/20 = 5 × 9/20 × 9 = 45/180 - Subtract the two like fractions:
8/180 - 45/180 = 8 - 45/180 = -37/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/90-5/20 4/90-10/20 4/90-5/40 12/90-5/20 4/90-15/20 4/90-5/60 20/90-5/20 4/90-25/20 28/90-5/20 4/90-35/20