Subtract 8/21 from 9/42
9/42 - 8/21 is -1/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
9/42 = 9 × 1/42 × 1 = 9/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
8/21 = 8 × 2/21 × 2 = 16/42 - Subtract the two like fractions:
9/42 - 16/42 = 9 - 16/42 = -7/42 - After reducing the fraction, the answer is -1/6
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