Subtract 15/27 from 21/84
21/84 - 15/27 is -11/36.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 27 is 756
Next, find the equivalent fraction of both fractional numbers with denominator 756 - For the 1st fraction, since 84 × 9 = 756,
21/84 = 21 × 9/84 × 9 = 189/756 - Likewise, for the 2nd fraction, since 27 × 28 = 756,
15/27 = 15 × 28/27 × 28 = 420/756 - Subtract the two like fractions:
189/756 - 420/756 = 189 - 420/756 = -231/756 - After reducing the fraction, the answer is -11/36
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