Subtract 40/81 from 42/2
1st number: 21 0/2, 2nd number: 40/81
42/2 - 40/81 is 1661/81.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 81 is 162
Next, find the equivalent fraction of both fractional numbers with denominator 162 - For the 1st fraction, since 2 × 81 = 162,
42/2 = 42 × 81/2 × 81 = 3402/162 - Likewise, for the 2nd fraction, since 81 × 2 = 162,
40/81 = 40 × 2/81 × 2 = 80/162 - Subtract the two like fractions:
3402/162 - 80/162 = 3402 - 80/162 = 3322/162 - After reducing the fraction, the answer is 1661/81
- In mixed form: 2041/81
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/2-40/81 42/2-80/81 42/4-40/81 42/6-40/81 42/10-40/81 42/14-40/81