Subtract 21/72 from 7/45
7/45 - 21/72 is -49/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 45 × 8 = 360,
7/45 = 7 × 8/45 × 8 = 56/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
21/72 = 21 × 5/72 × 5 = 105/360 - Subtract the two like fractions:
56/360 - 105/360 = 56 - 105/360 = -49/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/45-21/72 7/45-42/72 7/90-21/72 21/45-21/72 7/45-63/72 35/45-21/72 49/45-21/72