Subtract 90/21 from 27/8, Solve 3 3/8

Subtract 90/21 from 27/8

1^st number: 3 3/8, 2^nd number: 4 6/21

27/8 - 90/21 is -51/56.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
27/8 = 27 × 21/8 × 21 = 567/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
90/21 = 90 × 8/21 × 8 = 720/168
Subtract the two like fractions:
567/168 - 720/168 = 567 - 720/168 = -153/168
After reducing the fraction, the answer is -51/56

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