Answer
$$-3-\sqrt2i$$
Work Step by Step
Recall, the conjugate is the value that, when multiplied by the given expression, will yield only real numbers. This means that if the expression is in the form $a+bi$, the conjugate will be $a-bi$. In other words, $b$ will have the opposite sign in the conjugate. Considering this, we find that the conjugate is:
$$-3-\sqrt2i$$
