Subtract 20/16 from 7/81, Solve 7/81

Subtract 20/16 from 7/81

1^st number: 7/81, 2^nd number: 1 4/16

7/81 - 20/16 is -377/324.

Find the least common denominator or LCM of the two denominators:
LCM of 81 and 16 is 1296

Next, find the equivalent fraction of both fractional numbers with denominator 1296
For the 1st fraction, since 81 × 16 = 1296,
7/81 = 7 × 16/81 × 16 = 112/1296
Likewise, for the 2nd fraction, since 16 × 81 = 1296,
20/16 = 20 × 81/16 × 81 = 1620/1296
Subtract the two like fractions:
112/1296 - 1620/1296 = 112 - 1620/1296 = -1508/1296
After reducing the fraction, the answer is -377/324

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