Subtract 18/20 from 25/42
25/42 - 18/20 is -32/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
25/42 = 25 × 10/42 × 10 = 250/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Subtract the two like fractions:
250/420 - 378/420 = 250 - 378/420 = -128/420 - After reducing the fraction, the answer is -32/105
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