Subtract 72/42 from 5/20, Solve 5/20

Subtract 72/42 from 5/20

1^st number: 5/20, 2^nd number: 1 30/42

5/20 - 72/42 is -41/28.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
5/20 = 5 × 21/20 × 21 = 105/420
Likewise, for the 2nd fraction, since 42 × 10 = 420,
72/42 = 72 × 10/42 × 10 = 720/420
Subtract the two like fractions:
105/420 - 720/420 = 105 - 720/420 = -615/420
After reducing the fraction, the answer is -41/28

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