Subtract 63/18 from 10/21, Solve 10/21

Subtract 63/18 from 10/21

1^st number: 10/21, 2^nd number: 3 9/18

10/21 - 63/18 is -127/42.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 21 × 6 = 126,
10/21 = 10 × 6/21 × 6 = 60/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
63/18 = 63 × 7/18 × 7 = 441/126
Subtract the two like fractions:
60/126 - 441/126 = 60 - 441/126 = -381/126
After reducing the fraction, the answer is -127/42

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