Answers

Add 21/75 and 20/72

21/75 + 20/72 is 251/450.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 75 and 72 is 1800
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1800
2. For the 1st fraction, since 75 × 24 = 1800,
   21/75 = 21 × 24/75 × 24 = 504/1800
3. Likewise, for the 2nd fraction, since 72 × 25 = 1800,
   20/72 = 20 × 25/72 × 25 = 500/1800
4. Add the two like fractions:
   504/1800 + 500/1800 = 504 + 500/1800 = 1004/1800
5. 1004/1800 simplified gives 251/450
6. So, 21/75 + 20/72 = 251/450

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