Subtract 21/81 from 80/42
1st number: 1 38/42, 2nd number: 21/81
80/42 - 21/81 is 311/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 81 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 42 × 27 = 1134,
80/42 = 80 × 27/42 × 27 = 2160/1134 - Likewise, for the 2nd fraction, since 81 × 14 = 1134,
21/81 = 21 × 14/81 × 14 = 294/1134 - Subtract the two like fractions:
2160/1134 - 294/1134 = 2160 - 294/1134 = 1866/1134 - After reducing the fraction, the answer is 311/189
- In mixed form: 1122/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42-42/81 80/84-21/81 80/42-63/81