Subtract 18/21 from 15/72
15/72 - 18/21 is -109/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 21 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
15/72 = 15 × 7/72 × 7 = 105/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
18/21 = 18 × 24/21 × 24 = 432/504 - Subtract the two like fractions:
105/504 - 432/504 = 105 - 432/504 = -327/504 - After reducing the fraction, the answer is -109/168
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