Subtract 28/40 from 24/21, Solve 1 3/21

Subtract 28/40 from 24/21

1^st number: 1 3/21, 2^nd number: 28/40

24/21 - 28/40 is 31/70.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 21 × 40 = 840,
24/21 = 24 × 40/21 × 40 = 960/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
28/40 = 28 × 21/40 × 21 = 588/840
Subtract the two like fractions:
960/840 - 588/840 = 960 - 588/840 = 372/840
After reducing the fraction, the answer is 31/70

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