Subtract 70/15 from 70/21
1st number: 3 7/21, 2nd number: 4 10/15
70/21 - 70/15 is -4/3.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
70/21 = 70 × 5/21 × 5 = 350/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
70/15 = 70 × 7/15 × 7 = 490/105 - Subtract the two like fractions:
350/105 - 490/105 = 350 - 490/105 = -140/105 - After reducing the fraction, the answer is -4/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/42-70/15 70/21-70/30 70/63-70/15 70/21-70/45 70/21-70/75