Subtract 30/42 from 30/90
30/90 - 30/42 is -8/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
30/90 = 30 × 7/90 × 7 = 210/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
30/42 = 30 × 15/42 × 15 = 450/630 - Subtract the two like fractions:
210/630 - 450/630 = 210 - 450/630 = -240/630 - After reducing the fraction, the answer is -8/21
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