Subtract 80/81 from 70/20
1st number: 3 10/20, 2nd number: 80/81
70/20 - 80/81 is 407/162.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 81 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 20 × 81 = 1620,
70/20 = 70 × 81/20 × 81 = 5670/1620 - Likewise, for the 2nd fraction, since 81 × 20 = 1620,
80/81 = 80 × 20/81 × 20 = 1600/1620 - Subtract the two like fractions:
5670/1620 - 1600/1620 = 5670 - 1600/1620 = 4070/1620 - After reducing the fraction, the answer is 407/162
- In mixed form: 283/162
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/40-80/81 70/60-80/81