Subtract 7/81 from 4/90
4/90 - 7/81 is -17/405.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 90 × 9 = 810,
4/90 = 4 × 9/90 × 9 = 36/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
7/81 = 7 × 10/81 × 10 = 70/810 - Subtract the two like fractions:
36/810 - 70/810 = 36 - 70/810 = -34/810 - After reducing the fraction, the answer is -17/405
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