Subtract 3/18 from 3/42
3/42 - 3/18 is -2/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
3/42 = 3 × 3/42 × 3 = 9/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
3/18 = 3 × 7/18 × 7 = 21/126 - Subtract the two like fractions:
9/126 - 21/126 = 9 - 21/126 = -12/126 - After reducing the fraction, the answer is -2/21
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