Subtract 70/21 from 21/18
1st number: 1 3/18, 2nd number: 3 7/21
21/18 - 70/21 is -13/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
70/21 = 70 × 6/21 × 6 = 420/126 - Subtract the two like fractions:
147/126 - 420/126 = 147 - 420/126 = -273/126 - After reducing the fraction, the answer is -13/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18-70/21 21/36-70/21 21/18-70/42 63/18-70/21 21/54-70/21 21/18-70/63 21/90-70/21