Subtract 8/40 from 4/21
4/21 - 8/40 is -1/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
4/21 = 4 × 40/21 × 40 = 160/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
8/40 = 8 × 21/40 × 21 = 168/840 - Subtract the two like fractions:
160/840 - 168/840 = 160 - 168/840 = -8/840 - After reducing the fraction, the answer is -1/105
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