Subtract 20/10 from 15/42, Solve 15/42

Subtract 20/10 from 15/42

1^st number: 15/42, 2^nd number: 2 0/10

15/42 - 20/10 is -23/14.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 10 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
15/42 = 15 × 5/42 × 5 = 75/210
Likewise, for the 2nd fraction, since 10 × 21 = 210,
20/10 = 20 × 21/10 × 21 = 420/210
Subtract the two like fractions:
75/210 - 420/210 = 75 - 420/210 = -345/210
After reducing the fraction, the answer is -23/14

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