Subtract 8/21 from 5/15
5/15 - 8/21 is -1/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
5/15 = 5 × 7/15 × 7 = 35/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
8/21 = 8 × 5/21 × 5 = 40/105 - Subtract the two like fractions:
35/105 - 40/105 = 35 - 40/105 = -5/105 - After reducing the fraction, the answer is -1/21
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