Subtract 7/20 from 18/81
18/81 - 7/20 is -23/180.
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,
18/81 = 18 × 20/81 × 20 = 360/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
7/20 = 7 × 81/20 × 81 = 567/1620 - Subtract the two like fractions:
360/1620 - 567/1620 = 360 - 567/1620 = -207/1620 - After reducing the fraction, the answer is -23/180
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