Subtract 90/81 from 9/70
1st number: 9/70, 2nd number: 1 9/81
9/70 - 90/81 is -619/630.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 81 is 5670
Next, find the equivalent fraction of both fractional numbers with denominator 5670 - For the 1st fraction, since 70 × 81 = 5670,
9/70 = 9 × 81/70 × 81 = 729/5670 - Likewise, for the 2nd fraction, since 81 × 70 = 5670,
90/81 = 90 × 70/81 × 70 = 6300/5670 - Subtract the two like fractions:
729/5670 - 6300/5670 = 729 - 6300/5670 = -5571/5670 - After reducing the fraction, the answer is -619/630
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/70-90/81 27/70-90/81 45/70-90/81 63/70-90/81