Subtract 70/63 from 30/81
1st number: 30/81, 2nd number: 1 7/63
30/81 - 70/63 is -20/27.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 63 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 81 × 7 = 567,
30/81 = 30 × 7/81 × 7 = 210/567 - Likewise, for the 2nd fraction, since 63 × 9 = 567,
70/63 = 70 × 9/63 × 9 = 630/567 - Subtract the two like fractions:
210/567 - 630/567 = 210 - 630/567 = -420/567 - After reducing the fraction, the answer is -20/27
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/81-70/63 90/81-70/63