Subtract 28/56 from 7/21
7/21 - 28/56 is -1/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 56 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
7/21 = 7 × 8/21 × 8 = 56/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
28/56 = 28 × 3/56 × 3 = 84/168 - Subtract the two like fractions:
56/168 - 84/168 = 56 - 84/168 = -28/168 - After reducing the fraction, the answer is -1/6
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