Subtract 80/21 from 70/18
1st number: 3 16/18, 2nd number: 3 17/21
70/18 - 80/21 is 5/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
70/18 = 70 × 7/18 × 7 = 490/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
80/21 = 80 × 6/21 × 6 = 480/126 - Subtract the two like fractions:
490/126 - 480/126 = 490 - 480/126 = 10/126 - After reducing the fraction, the answer is 5/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/36-80/21 70/18-80/42 70/54-80/21 70/18-80/63 70/90-80/21