Subtract 18/36 from 1/21
1/21 - 18/36 is -19/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 36 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 21 × 12 = 252,
1/21 = 1 × 12/21 × 12 = 12/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
18/36 = 18 × 7/36 × 7 = 126/252 - Subtract the two like fractions:
12/252 - 126/252 = 12 - 126/252 = -114/252 - After reducing the fraction, the answer is -19/42
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