Subtract 10/9 from 42/21
1st number: 2 0/21, 2nd number: 1 1/9
42/21 - 10/9 is 8/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
42/21 = 42 × 3/21 × 3 = 126/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
10/9 = 10 × 7/9 × 7 = 70/63 - Subtract the two like fractions:
126/63 - 70/63 = 126 - 70/63 = 56/63 - After reducing the fraction, the answer is 8/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21-10/9 42/21-20/9 42/21-10/18 42/21-30/9 42/63-10/9 42/21-10/27 42/21-50/9 42/21-10/45 42/21-70/9 42/21-10/63