Subtract 18/72 from 1/21
1/21 - 18/72 is -17/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 21 × 24 = 504,
1/21 = 1 × 24/21 × 24 = 24/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
18/72 = 18 × 7/72 × 7 = 126/504 - Subtract the two like fractions:
24/504 - 126/504 = 24 - 126/504 = -102/504 - After reducing the fraction, the answer is -17/84
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