Subtract 54/8 from 28/21, Solve 1 7/21

Subtract 54/8 from 28/21

1^st number: 1 7/21, 2^nd number: 6 6/8

28/21 - 54/8 is -65/12.

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

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 21 × 8 = 168,
28/21 = 28 × 8/21 × 8 = 224/168
Likewise, for the 2nd fraction, since 8 × 21 = 168,
54/8 = 54 × 21/8 × 21 = 1134/168
Subtract the two like fractions:
224/168 - 1134/168 = 224 - 1134/168 = -910/168
After reducing the fraction, the answer is -65/12

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