Subtract 70/21 from 42/18
1st number: 2 6/18, 2nd number: 3 7/21
42/18 - 70/21 is -1/1.
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,
42/18 = 42 × 7/18 × 7 = 294/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
70/21 = 70 × 6/21 × 6 = 420/126 - Subtract the two like fractions:
294/126 - 420/126 = 294 - 420/126 = -126/126 - After reducing the fraction, the answer is -1/1
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/18-70/21 42/36-70/21 42/18-70/42 42/54-70/21 42/18-70/63 42/90-70/21