Subtract 42/24 from 5/21, Solve 5/21

Subtract 42/24 from 5/21

1^st number: 5/21, 2^nd number: 1 18/24

5/21 - 42/24 is -127/84.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 24 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 21 × 8 = 168,
5/21 = 5 × 8/21 × 8 = 40/168
Likewise, for the 2nd fraction, since 24 × 7 = 168,
42/24 = 42 × 7/24 × 7 = 294/168
Subtract the two like fractions:
40/168 - 294/168 = 40 - 294/168 = -254/168
After reducing the fraction, the answer is -127/84

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