Subtract 20/8 from 9/42
1st number: 9/42, 2nd number: 2 4/8
9/42 - 20/8 is -16/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
9/42 = 9 × 4/42 × 4 = 36/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
20/8 = 20 × 21/8 × 21 = 420/168 - Subtract the two like fractions:
36/168 - 420/168 = 36 - 420/168 = -384/168 - After reducing the fraction, the answer is -16/7
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