Subtract 42/21 from 3/2
1st number: 1 1/2, 2nd number: 2 0/21
3/2 - 42/21 is -1/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 2 × 21 = 42,
3/2 = 3 × 21/2 × 21 = 63/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
42/21 = 42 × 2/21 × 2 = 84/42 - Subtract the two like fractions:
63/42 - 84/42 = 63 - 84/42 = -21/42 - After reducing the fraction, the answer is -1/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/2-42/21 3/2-84/21 3/4-42/21 9/2-42/21 3/6-42/21 3/2-42/63 15/2-42/21 3/10-42/21 21/2-42/21 3/14-42/21