Subtract 10/15 from 10/21
10/21 - 10/15 is -4/21.
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,
10/21 = 10 × 5/21 × 5 = 50/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
10/15 = 10 × 7/15 × 7 = 70/105 - Subtract the two like fractions:
50/105 - 70/105 = 50 - 70/105 = -20/105 - After reducing the fraction, the answer is -4/21
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