Subtract 18/90 from 8/42
8/42 - 18/90 is -1/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
8/42 = 8 × 15/42 × 15 = 120/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
18/90 = 18 × 7/90 × 7 = 126/630 - Subtract the two like fractions:
120/630 - 126/630 = 120 - 126/630 = -6/630 - After reducing the fraction, the answer is -1/105
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