Answer:
[tex] 81{x}^{2} + 18x \sqrt{2} + 2 [/tex]
Step-by-step explanation:
[tex](9x + \sqrt{2} )(9x + \sqrt{2} ) \\ = {(9x)}^{2} + ( \sqrt{2} + \sqrt{2} ) \times 9x + \sqrt{2} \times \sqrt{2} \\ = 81 {x}^{2} + 2 \sqrt{2} \times 9x + 2 \\ = 81{x}^{2} + 18x \sqrt{2} + 2 \\ [/tex]
