Answers

Subtract 54/72 from 21/30

21/30 - 54/72 is -1/20.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 30 and 72 is 360
   
   Next, find the equivalent fraction of both fractional numbers with denominator 360
2. For the 1st fraction, since 30 × 12 = 360,
   21/30 = 21 × 12/30 × 12 = 252/360
3. Likewise, for the 2nd fraction, since 72 × 5 = 360,
   54/72 = 54 × 5/72 × 5 = 270/360
4. Subtract the two like fractions:
   252/360 - 270/360 = 252 - 270/360 = -18/360
5. After reducing the fraction, the answer is -1/20

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