Subtract 20/18 from 20/42
1st number: 20/42, 2nd number: 1 2/18
20/42 - 20/18 is -40/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
20/42 = 20 × 3/42 × 3 = 60/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
20/18 = 20 × 7/18 × 7 = 140/126 - Subtract the two like fractions:
60/126 - 140/126 = 60 - 140/126 = -80/126 - After reducing the fraction, the answer is -40/63
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