Subtract 9/42 from 21/81
21/81 - 9/42 is 17/378.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 42 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 81 × 14 = 1134,
21/81 = 21 × 14/81 × 14 = 294/1134 - Likewise, for the 2nd fraction, since 42 × 27 = 1134,
9/42 = 9 × 27/42 × 27 = 243/1134 - Subtract the two like fractions:
294/1134 - 243/1134 = 294 - 243/1134 = 51/1134 - After reducing the fraction, the answer is 17/378
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