Subtract 15/21 from 42/9
1st number: 4 6/9, 2nd number: 15/21
42/9 - 15/21 is 83/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
42/9 = 42 × 7/9 × 7 = 294/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
15/21 = 15 × 3/21 × 3 = 45/63 - Subtract the two like fractions:
294/63 - 45/63 = 294 - 45/63 = 249/63 - After reducing the fraction, the answer is 83/21
- In mixed form: 320/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/9-15/21 42/9-30/21 42/18-15/21 42/9-15/42 42/9-45/21 42/27-15/21 42/9-15/63 42/9-75/21 42/45-15/21 42/63-15/21