Answer
$\sqrt 2-x$
Work Step by Step
We are told on page 442 that the conjugate of the term $(a+b)$ is the term$(a-b)$.
Therefore, if $a=\sqrt 2$ and $b=x$, then the conjugate of the given expression is $a-b=\sqrt 2-x$.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.