Subtract 21/81 from 5/80
5/80 - 21/81 is -85/432.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 81 is 6480
Next, find the equivalent fraction of both fractional numbers with denominator 6480 - For the 1st fraction, since 80 × 81 = 6480,
5/80 = 5 × 81/80 × 81 = 405/6480 - Likewise, for the 2nd fraction, since 81 × 80 = 6480,
21/81 = 21 × 80/81 × 80 = 1680/6480 - Subtract the two like fractions:
405/6480 - 1680/6480 = 405 - 1680/6480 = -1275/6480 - After reducing the fraction, the answer is -85/432
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