Subtract 21/63 from 15/70
15/70 - 21/63 is -5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 63 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 70 × 9 = 630,
15/70 = 15 × 9/70 × 9 = 135/630 - Likewise, for the 2nd fraction, since 63 × 10 = 630,
21/63 = 21 × 10/63 × 10 = 210/630 - Subtract the two like fractions:
135/630 - 210/630 = 135 - 210/630 = -75/630 - After reducing the fraction, the answer is -5/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/70-21/63 15/70-42/63 45/70-21/63 75/70-21/63