Question

10..................................

Answer 1

Answer:

The answer is 7 ⇒ answer (C)

Step-by-step explanation:

∵ (3 + √2)(3 - √2) =

  9 - 3√2 + 3√2 - 2 = 9 - 2 = 7

∴ The answer is 7

Answer 2

For this case we must simplify the following expression:

$(3+ \sqrt {2}) (3- \sqrt {2})$

We apply distributive property:

$9-3 \sqrt {2} +3 \sqrt {2} - \sqrt {2} * \sqrt {2} =$

We take into account that different signs are subtracted and the sign of the major is placed:

$9 - (\sqrt {2}) ^ 2 =\\9-2 =$

We take into account that different signs are subtracted and the sign of the major is placed:

$9-2=7$

So, we have:

$(3+ \sqrt {2}) (3- \sqrt {2}) = 7$

Answer:

Option C