Answer
See explanation
Work Step by Step
Conjugates are multiplied in the same way multiplication is done for any binomials.
The following formula can be used to multiply any two conjugates.
$$(A+B)(A-B) = A^2-B^2$$
Example:
$$(3-\sqrt 7)(3+\sqrt 7)=3^2-(\sqrt 7)^2=9-7=2$$
