Subtract 30/45 from 18/42
18/42 - 30/45 is -5/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
18/42 = 18 × 15/42 × 15 = 270/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
30/45 = 30 × 14/45 × 14 = 420/630 - Subtract the two like fractions:
270/630 - 420/630 = 270 - 420/630 = -150/630 - After reducing the fraction, the answer is -5/21
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