Answer:
[tex] {x}^{2} + 6x + 9 \\ [/tex]
Step-by-step explanation:
[tex] {(x + 3)}^{2} \\ (x + 3)(x + 3) \\ x(x + 3) + 3(x + 3) \\ {x}^{2} + 3x + 3x + 9 \\ {x}^{2} + 6x + 9 \\ [/tex]
