Subtract 18/4 from 20/42
1st number: 20/42, 2nd number: 4 2/4
20/42 - 18/4 is -169/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 4 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
20/42 = 20 × 2/42 × 2 = 40/84 - Likewise, for the 2nd fraction, since 4 × 21 = 84,
18/4 = 18 × 21/4 × 21 = 378/84 - Subtract the two like fractions:
40/84 - 378/84 = 40 - 378/84 = -338/84 - After reducing the fraction, the answer is -169/42
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