Subtract 81/20 from 18/42
1st number: 18/42, 2nd number: 4 1/20
18/42 - 81/20 is -507/140.
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,
18/42 = 18 × 10/42 × 10 = 180/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
81/20 = 81 × 21/20 × 21 = 1701/420 - Subtract the two like fractions:
180/420 - 1701/420 = 180 - 1701/420 = -1521/420 - After reducing the fraction, the answer is -507/140
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