Subtract 20/5 from 7/84, Solve 7/84

Subtract 20/5 from 7/84

1^st number: 7/84, 2^nd number: 4 0/5

7/84 - 20/5 is -47/12.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 5 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 84 × 5 = 420,
7/84 = 7 × 5/84 × 5 = 35/420
Likewise, for the 2nd fraction, since 5 × 84 = 420,
20/5 = 20 × 84/5 × 84 = 1680/420
Subtract the two like fractions:
35/420 - 1680/420 = 35 - 1680/420 = -1645/420
After reducing the fraction, the answer is -47/12

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