Subtract 3/18 from 21/70
21/70 - 3/18 is 2/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 18 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 70 × 9 = 630,
21/70 = 21 × 9/70 × 9 = 189/630 - Likewise, for the 2nd fraction, since 18 × 35 = 630,
3/18 = 3 × 35/18 × 35 = 105/630 - Subtract the two like fractions:
189/630 - 105/630 = 189 - 105/630 = 84/630 - After reducing the fraction, the answer is 2/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/70-3/18 21/70-6/18 21/70-3/36 63/70-3/18 21/70-9/18 21/70-3/54 21/70-15/18 21/70-3/90 21/70-21/18