Subtract 70/18 from 8/21
1st number: 8/21, 2nd number: 3 16/18
8/21 - 70/18 is -221/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
8/21 = 8 × 6/21 × 6 = 48/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
70/18 = 70 × 7/18 × 7 = 490/126 - Subtract the two like fractions:
48/126 - 490/126 = 48 - 490/126 = -442/126 - After reducing the fraction, the answer is -221/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21-70/18 8/42-70/18 8/21-70/36 24/21-70/18 8/63-70/18 8/21-70/54 40/21-70/18 8/21-70/90 56/21-70/18