Subtract 42/63 from 18/30
18/30 - 42/63 is -1/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 63 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 30 × 21 = 630,
18/30 = 18 × 21/30 × 21 = 378/630 - Likewise, for the 2nd fraction, since 63 × 10 = 630,
42/63 = 42 × 10/63 × 10 = 420/630 - Subtract the two like fractions:
378/630 - 420/630 = 378 - 420/630 = -42/630 - After reducing the fraction, the answer is -1/15
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