Subtract 45/40 from 25/21, Solve 1 4/21

Subtract 45/40 from 25/21

1^st number: 1 4/21, 2^nd number: 1 5/40

25/21 - 45/40 is 11/168.

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,
25/21 = 25 × 40/21 × 40 = 1000/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
45/40 = 45 × 21/40 × 21 = 945/840
Subtract the two like fractions:
1000/840 - 945/840 = 1000 - 945/840 = 55/840
After reducing the fraction, the answer is 11/168

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