Subtract 7/20 from 4/45
4/45 - 7/20 is -47/180.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
4/45 = 4 × 4/45 × 4 = 16/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
7/20 = 7 × 9/20 × 9 = 63/180 - Subtract the two like fractions:
16/180 - 63/180 = 16 - 63/180 = -47/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/45-7/20 4/45-14/20 4/90-7/20 4/45-7/40 12/45-7/20 4/45-21/20 4/45-7/60 20/45-7/20 4/45-35/20 28/45-7/20 4/45-49/20