Subtract 21/70 from 8/81
8/81 - 21/70 is -163/810.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 70 is 5670
Next, find the equivalent fraction of both fractional numbers with denominator 5670 - For the 1st fraction, since 81 × 70 = 5670,
8/81 = 8 × 70/81 × 70 = 560/5670 - Likewise, for the 2nd fraction, since 70 × 81 = 5670,
21/70 = 21 × 81/70 × 81 = 1701/5670 - Subtract the two like fractions:
560/5670 - 1701/5670 = 560 - 1701/5670 = -1141/5670 - After reducing the fraction, the answer is -163/810
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