Subtract 72/21 from 40/60, Solve 40/60

Subtract 72/21 from 40/60

1^st number: 40/60, 2^nd number: 3 9/21

40/60 - 72/21 is -58/21.

Find the least common denominator or LCM of the two denominators:
LCM of 60 and 21 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 60 × 7 = 420,
40/60 = 40 × 7/60 × 7 = 280/420
Likewise, for the 2nd fraction, since 21 × 20 = 420,
72/21 = 72 × 20/21 × 20 = 1440/420
Subtract the two like fractions:
280/420 - 1440/420 = 280 - 1440/420 = -1160/420
After reducing the fraction, the answer is -58/21

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