Subtract 42/84 from 18/20
18/20 - 42/84 is 2/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
42/84 = 42 × 5/84 × 5 = 210/420 - Subtract the two like fractions:
378/420 - 210/420 = 378 - 210/420 = 168/420 - After reducing the fraction, the answer is 2/5
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