Subtract 90/27 from 72/42, Solve 1 30/42

Subtract 90/27 from 72/42

1^st number: 1 30/42, 2^nd number: 3 9/27

72/42 - 90/27 is -34/21.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 27 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 42 × 9 = 378,
72/42 = 72 × 9/42 × 9 = 648/378
Likewise, for the 2nd fraction, since 27 × 14 = 378,
90/27 = 90 × 14/27 × 14 = 1260/378
Subtract the two like fractions:
648/378 - 1260/378 = 648 - 1260/378 = -612/378
After reducing the fraction, the answer is -34/21

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