Subtract 49/80 from 30/21, Solve 1 9/21

Subtract 49/80 from 30/21

1^st number: 1 9/21, 2^nd number: 49/80

30/21 - 49/80 is 457/560.

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
For the 1st fraction, since 21 × 80 = 1680,
30/21 = 30 × 80/21 × 80 = 2400/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
49/80 = 49 × 21/80 × 21 = 1029/1680
Subtract the two like fractions:
2400/1680 - 1029/1680 = 2400 - 1029/1680 = 1371/1680
After reducing the fraction, the answer is 457/560

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