Subtract 80/90 from 70/21
1st number: 3 7/21, 2nd number: 80/90
70/21 - 80/90 is 22/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
70/21 = 70 × 30/21 × 30 = 2100/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
80/90 = 80 × 7/90 × 7 = 560/630 - Subtract the two like fractions:
2100/630 - 560/630 = 2100 - 560/630 = 1540/630 - After reducing the fraction, the answer is 22/9
- In mixed form: 24/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/42-80/90 70/63-80/90