Subtract 21/16 from 30/42, Solve 30/42

Subtract 21/16 from 30/42

1^st number: 30/42, 2^nd number: 1 5/16

30/42 - 21/16 is -67/112.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 16 is 336

Next, find the equivalent fraction of both fractional numbers with denominator 336
For the 1st fraction, since 42 × 8 = 336,
30/42 = 30 × 8/42 × 8 = 240/336
Likewise, for the 2nd fraction, since 16 × 21 = 336,
21/16 = 21 × 21/16 × 21 = 441/336
Subtract the two like fractions:
240/336 - 441/336 = 240 - 441/336 = -201/336
After reducing the fraction, the answer is -67/112

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