Subtract 10/21 from 21/72
21/72 - 10/21 is -31/168.
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,
21/72 = 21 × 7/72 × 7 = 147/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
10/21 = 10 × 24/21 × 24 = 240/504 - Subtract the two like fractions:
147/504 - 240/504 = 147 - 240/504 = -93/504 - After reducing the fraction, the answer is -31/168
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