Subtract 2/5 from 8/21
8/21 - 2/5 is -2/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
8/21 = 8 × 5/21 × 5 = 40/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
2/5 = 2 × 21/5 × 21 = 42/105 - Subtract the two like fractions:
40/105 - 42/105 = 40 - 42/105 = -2/105
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