Subtract 27/30 from 18/42
18/42 - 27/30 is -33/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
27/30 = 27 × 7/30 × 7 = 189/210 - Subtract the two like fractions:
90/210 - 189/210 = 90 - 189/210 = -99/210 - After reducing the fraction, the answer is -33/70
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