Subtract 70/81 from 30/90
30/90 - 70/81 is -43/81.
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,
30/90 = 30 × 9/90 × 9 = 270/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
70/81 = 70 × 10/81 × 10 = 700/810 - Subtract the two like fractions:
270/810 - 700/810 = 270 - 700/810 = -430/810 - After reducing the fraction, the answer is -43/81
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