Subtract 9/5 from 63/42, Solve 1 21/42

Subtract 9/5 from 63/42

1^st number: 1 21/42, 2^nd number: 1 4/5

63/42 - 9/5 is -3/10.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 5 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 5 × 42 = 210,
9/5 = 9 × 42/5 × 42 = 378/210
Subtract the two like fractions:
315/210 - 378/210 = 315 - 378/210 = -63/210
After reducing the fraction, the answer is -3/10

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