Subtract 90/21 from 5/80, Solve 5/80

Subtract 90/21 from 5/80

1^st number: 5/80, 2^nd number: 4 6/21

5/80 - 90/21 is -473/112.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 80 × 21 = 1680,
5/80 = 5 × 21/80 × 21 = 105/1680
Likewise, for the 2nd fraction, since 21 × 80 = 1680,
90/21 = 90 × 80/21 × 80 = 7200/1680
Subtract the two like fractions:
105/1680 - 7200/1680 = 105 - 7200/1680 = -7095/1680
After reducing the fraction, the answer is -473/112

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