Subtract 9/42 from 12/21
12/21 - 9/42 is 5/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
12/21 = 12 × 2/21 × 2 = 24/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
9/42 = 9 × 1/42 × 1 = 9/42 - Subtract the two like fractions:
24/42 - 9/42 = 24 - 9/42 = 15/42 - After reducing the fraction, the answer is 5/14
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