Subtract 10/21 from 15/70
15/70 - 10/21 is -11/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
15/70 = 15 × 3/70 × 3 = 45/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
10/21 = 10 × 10/21 × 10 = 100/210 - Subtract the two like fractions:
45/210 - 100/210 = 45 - 100/210 = -55/210 - After reducing the fraction, the answer is -11/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/70-10/21 15/70-20/21 15/70-10/42 45/70-10/21 15/70-30/21 15/70-10/63 75/70-10/21 15/70-50/21 15/70-70/21