Subtract 80/21 from 72/45, Solve 1 27/45

Subtract 80/21 from 72/45

1^st number: 1 27/45, 2^nd number: 3 17/21

72/45 - 80/21 is -232/105.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
72/45 = 72 × 7/45 × 7 = 504/315
Likewise, for the 2nd fraction, since 21 × 15 = 315,
80/21 = 80 × 15/21 × 15 = 1200/315
Subtract the two like fractions:
504/315 - 1200/315 = 504 - 1200/315 = -696/315
After reducing the fraction, the answer is -232/105

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