Subtract 75/90 from 70/21
1st number: 3 7/21, 2nd number: 75/90
70/21 - 75/90 is 5/2.
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,
75/90 = 75 × 7/90 × 7 = 525/630 - Subtract the two like fractions:
2100/630 - 525/630 = 2100 - 525/630 = 1575/630 - After reducing the fraction, the answer is 5/2
- In mixed form: 21/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/42-75/90 70/63-75/90