Answers

Subtract 63/80 from 42/21

1^st number: 2 0/21, 2^nd number: 63/80

42/21 - 63/80 is 97/80.

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,
   42/21 = 42 × 80/21 × 80 = 3360/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   63/80 = 63 × 21/80 × 21 = 1323/1680
4. Subtract the two like fractions:
   3360/1680 - 1323/1680 = 3360 - 1323/1680 = 2037/1680
5. After reducing the fraction, the answer is 97/80
6. In mixed form: 117/80

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