Subtract 30/40 from 8/42
8/42 - 30/40 is -47/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
8/42 = 8 × 20/42 × 20 = 160/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
30/40 = 30 × 21/40 × 21 = 630/840 - Subtract the two like fractions:
160/840 - 630/840 = 160 - 630/840 = -470/840 - After reducing the fraction, the answer is -47/84
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