Subtract 81/32 from 7/21, Solve 7/21

Subtract 81/32 from 7/21

1^st number: 7/21, 2^nd number: 2 17/32

7/21 - 81/32 is -211/96.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 32 is 672

Next, find the equivalent fraction of both fractional numbers with denominator 672
For the 1st fraction, since 21 × 32 = 672,
7/21 = 7 × 32/21 × 32 = 224/672
Likewise, for the 2nd fraction, since 32 × 21 = 672,
81/32 = 81 × 21/32 × 21 = 1701/672
Subtract the two like fractions:
224/672 - 1701/672 = 224 - 1701/672 = -1477/672
After reducing the fraction, the answer is -211/96

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