Subtract 20/25 from 7/81
7/81 - 20/25 is -289/405.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 25 is 2025
Next, find the equivalent fraction of both fractional numbers with denominator 2025 - For the 1st fraction, since 81 × 25 = 2025,
7/81 = 7 × 25/81 × 25 = 175/2025 - Likewise, for the 2nd fraction, since 25 × 81 = 2025,
20/25 = 20 × 81/25 × 81 = 1620/2025 - Subtract the two like fractions:
175/2025 - 1620/2025 = 175 - 1620/2025 = -1445/2025 - After reducing the fraction, the answer is -289/405
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