Subtract 21/72 from 8/42
8/42 - 21/72 is -17/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 42 × 12 = 504,
8/42 = 8 × 12/42 × 12 = 96/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
21/72 = 21 × 7/72 × 7 = 147/504 - Subtract the two like fractions:
96/504 - 147/504 = 96 - 147/504 = -51/504 - After reducing the fraction, the answer is -17/168
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