Subtract 28/32 from 18/21
18/21 - 28/32 is -1/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 32 is 672
Next, find the equivalent fraction of both fractional numbers with denominator 672 - For the 1st fraction, since 21 × 32 = 672,
18/21 = 18 × 32/21 × 32 = 576/672 - Likewise, for the 2nd fraction, since 32 × 21 = 672,
28/32 = 28 × 21/32 × 21 = 588/672 - Subtract the two like fractions:
576/672 - 588/672 = 576 - 588/672 = -12/672 - After reducing the fraction, the answer is -1/56
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