Subtract 36/15 from 63/42, Solve 1 21/42

Subtract 36/15 from 63/42

1^st number: 1 21/42, 2^nd number: 2 6/15

63/42 - 36/15 is -9/10.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 15 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
63/42 = 63 × 5/42 × 5 = 315/210
Likewise, for the 2nd fraction, since 15 × 14 = 210,
36/15 = 36 × 14/15 × 14 = 504/210
Subtract the two like fractions:
315/210 - 504/210 = 315 - 504/210 = -189/210
After reducing the fraction, the answer is -9/10

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