Subtract 72/21 from 36/56, Solve 36/56

Subtract 72/21 from 36/56

1^st number: 36/56, 2^nd number: 3 9/21

36/56 - 72/21 is -39/14.

Find the least common denominator or LCM of the two denominators:
LCM of 56 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 56 × 3 = 168,
36/56 = 36 × 3/56 × 3 = 108/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
72/21 = 72 × 8/21 × 8 = 576/168
Subtract the two like fractions:
108/168 - 576/168 = 108 - 576/168 = -468/168
After reducing the fraction, the answer is -39/14

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