Subtract 9/12 from 18/42
18/42 - 9/12 is -9/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
18/42 = 18 × 2/42 × 2 = 36/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
9/12 = 9 × 7/12 × 7 = 63/84 - Subtract the two like fractions:
36/84 - 63/84 = 36 - 63/84 = -27/84 - After reducing the fraction, the answer is -9/28
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