Subtract 42/18 from 20/42, Solve 20/42

Subtract 42/18 from 20/42

1^st number: 20/42, 2^nd number: 2 6/18

20/42 - 42/18 is -13/7.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 42 × 3 = 126,
20/42 = 20 × 3/42 × 3 = 60/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
42/18 = 42 × 7/18 × 7 = 294/126
Subtract the two like fractions:
60/126 - 294/126 = 60 - 294/126 = -234/126
After reducing the fraction, the answer is -13/7

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