Subtract 15/30 from 84/21
1st number: 4 0/21, 2nd number: 15/30
84/21 - 15/30 is 7/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
84/21 = 84 × 10/21 × 10 = 840/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
15/30 = 15 × 7/30 × 7 = 105/210 - Subtract the two like fractions:
840/210 - 105/210 = 840 - 105/210 = 735/210 - After reducing the fraction, the answer is 7/2
- In mixed form: 31/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/42-15/30 84/21-15/60 84/21-45/30 84/63-15/30 84/21-15/90 84/21-75/30