Subtract 84/45 from 40/21, Solve 1 19/21

Subtract 84/45 from 40/21

1^st number: 1 19/21, 2^nd number: 1 39/45

40/21 - 84/45 is 4/105.

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

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 21 × 15 = 315,
40/21 = 40 × 15/21 × 15 = 600/315
Likewise, for the 2nd fraction, since 45 × 7 = 315,
84/45 = 84 × 7/45 × 7 = 588/315
Subtract the two like fractions:
600/315 - 588/315 = 600 - 588/315 = 12/315
After reducing the fraction, the answer is 4/105

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