Subtract 45/30 from 21/72
1st number: 21/72, 2nd number: 1 15/30
21/72 - 45/30 is -29/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 30 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 30 × 12 = 360,
45/30 = 45 × 12/30 × 12 = 540/360 - Subtract the two like fractions:
105/360 - 540/360 = 105 - 540/360 = -435/360 - After reducing the fraction, the answer is -29/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/72-45/30 21/72-90/30 21/72-45/60 63/72-45/30 21/72-45/90