Subtract 42/90 from 21/3
1st number: 7 0/3, 2nd number: 42/90
21/3 - 42/90 is 98/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 3 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 3 × 30 = 90,
21/3 = 21 × 30/3 × 30 = 630/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
42/90 = 42 × 1/90 × 1 = 42/90 - Subtract the two like fractions:
630/90 - 42/90 = 630 - 42/90 = 588/90 - After reducing the fraction, the answer is 98/15
- In mixed form: 68/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/3-42/90 21/3-84/90 21/6-42/90 63/3-42/90 21/9-42/90 21/15-42/90