Respuesta :

Answer:

81

Step-by-step explanation:

[tex] {x}^{2} + 18x + {(( \frac{1}{2})(18)) }^{2} [/tex]

[tex] {x}^{2} + 18x + {9}^{2} [/tex]

[tex] {x}^{2} + 18x + 81[/tex]

[tex] {(x + 9)}^{2} [/tex]