Subtract 21/81 from 4/30
4/30 - 21/81 is -17/135.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 30 × 27 = 810,
4/30 = 4 × 27/30 × 27 = 108/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
21/81 = 21 × 10/81 × 10 = 210/810 - Subtract the two like fractions:
108/810 - 210/810 = 108 - 210/810 = -102/810 - After reducing the fraction, the answer is -17/135
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