If V = {x : x is a natural number and x² = 25}, what is the roster form of V?
The defining equation x² = 25 has two integer solutions, x = 5 and x = -5, because both 5² and (-5)² equal 25. However, the set-builder description restricts x to natural numbers. The negative value -5 is therefore excluded, leaving only x = 5. The number 25 is not a solution value for x; it is the value of x², so option D confuses the square with the number being squared. Option B ignores the natural-number restriction, and option C keeps only the inadmissible negative solution. Thus the roster form is V = {5}, making option A correct.
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