Subtract 21/42 from 18/2
1st number: 9 0/2, 2nd number: 21/42
18/2 - 21/42 is 17/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 2 × 21 = 42,
18/2 = 18 × 21/2 × 21 = 378/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
21/42 = 21 × 1/42 × 1 = 21/42 - Subtract the two like fractions:
378/42 - 21/42 = 378 - 21/42 = 357/42 - After reducing the fraction, the answer is 17/2
- In mixed form: 81/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/2-21/42 18/4-21/42 18/2-21/84 54/2-21/42 18/2-63/42 18/6-21/42 90/2-21/42 18/10-21/42 18/14-21/42