Subtract 15/21 from 3/8, Solve 3/8

Subtract 15/21 from 3/8

3/8 - 15/21 is -19/56.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
3/8 = 3 × 21/8 × 21 = 63/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
15/21 = 15 × 8/21 × 8 = 120/168
Subtract the two like fractions:
63/168 - 120/168 = 63 - 120/168 = -57/168
After reducing the fraction, the answer is -19/56

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