Subtract 90/8 from 20/42
1st number: 20/42, 2nd number: 11 2/8
20/42 - 90/8 is -905/84.
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,
20/42 = 20 × 4/42 × 4 = 80/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
90/8 = 90 × 21/8 × 21 = 1890/168 - Subtract the two like fractions:
80/168 - 1890/168 = 80 - 1890/168 = -1810/168 - After reducing the fraction, the answer is -905/84
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