Answers

Subtract 12/80 from 90/21

1^st number: 4 6/21, 2^nd number: 12/80

90/21 - 12/80 is 579/140.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 80 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 21 × 80 = 1680,
   90/21 = 90 × 80/21 × 80 = 7200/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   12/80 = 12 × 21/80 × 21 = 252/1680
4. Subtract the two like fractions:
   7200/1680 - 252/1680 = 7200 - 252/1680 = 6948/1680
5. After reducing the fraction, the answer is 579/140
6. In mixed form: 419/140

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