Respuesta :

gmany

[tex]n-a\ number\\\\(n+9)^2=n^2+2(n)(9)+9^2=n^2+18n+81\\\\Used\ (a+b)^2=a^2+2ab+b^2[/tex]

Answer:

   (x+9)²

Step-by-step explanation:

The square of the sum of a number and 9 is in terms of x, is (x+9)²

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