Subtract 7/9 from 20/42
20/42 - 7/9 is -19/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 9 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 9 × 14 = 126,
7/9 = 7 × 14/9 × 14 = 98/126 - Subtract the two like fractions:
60/126 - 98/126 = 60 - 98/126 = -38/126 - After reducing the fraction, the answer is -19/63
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