For this case we must simplify the following expression:
[tex](3+ \sqrt {2}) (3- \sqrt {2})[/tex]
We apply distributive property:
[tex]9-3 \sqrt {2} +3 \sqrt {2} - \sqrt {2} * \sqrt {2} =[/tex]
We take into account that different signs are subtracted and the sign of the major is placed:
[tex]9 - (\sqrt {2}) ^ 2 =\\9-2 =[/tex]
We take into account that different signs are subtracted and the sign of the major is placed:
[tex]9-2=7[/tex]
So, we have:
[tex](3+ \sqrt {2}) (3- \sqrt {2}) = 7[/tex]
Answer:
Option C
