Subtract 9/20 from 30/81
30/81 - 9/20 is -43/540.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 20 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 81 × 20 = 1620,
30/81 = 30 × 20/81 × 20 = 600/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
9/20 = 9 × 81/20 × 81 = 729/1620 - Subtract the two like fractions:
600/1620 - 729/1620 = 600 - 729/1620 = -129/1620 - After reducing the fraction, the answer is -43/540
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