Subtract 42/27 from 10/20, Solve 10/20

Subtract 42/27 from 10/20

1^st number: 10/20, 2^nd number: 1 15/27

10/20 - 42/27 is -19/18.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 27 is 540

Next, find the equivalent fraction of both fractional numbers with denominator 540
For the 1st fraction, since 20 × 27 = 540,
10/20 = 10 × 27/20 × 27 = 270/540
Likewise, for the 2nd fraction, since 27 × 20 = 540,
42/27 = 42 × 20/27 × 20 = 840/540
Subtract the two like fractions:
270/540 - 840/540 = 270 - 840/540 = -570/540
After reducing the fraction, the answer is -19/18

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