Subtract 42/84 from 1/40
1/40 - 42/84 is -19/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 84 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
1/40 = 1 × 21/40 × 21 = 21/840 - Likewise, for the 2nd fraction, since 84 × 10 = 840,
42/84 = 42 × 10/84 × 10 = 420/840 - Subtract the two like fractions:
21/840 - 420/840 = 21 - 420/840 = -399/840 - After reducing the fraction, the answer is -19/40
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