Subtract 27/20 from 21/72
1st number: 21/72, 2nd number: 1 7/20
21/72 - 27/20 is -127/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 20 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
21/72 = 21 × 5/72 × 5 = 105/360 - Likewise, for the 2nd fraction, since 20 × 18 = 360,
27/20 = 27 × 18/20 × 18 = 486/360 - Subtract the two like fractions:
105/360 - 486/360 = 105 - 486/360 = -381/360 - After reducing the fraction, the answer is -127/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/72-27/20 21/72-54/20 21/72-27/40 63/72-27/20 21/72-81/20 21/72-27/60