Given:
[tex](6\text{ - }\sqrt[]{8})(6\text{ + }\sqrt[]{8})[/tex]We multiply by following the rules of expansion:
First step: Open the bracket:
[tex]\begin{gathered} \text{= 6(6 + }\sqrt[]{8})\text{ - }\sqrt[]{8}(6\text{ + }\sqrt[]{8}) \\ =\text{ 36 + 6}\sqrt[]{8}\text{ -6}\sqrt[]{8}\text{ - (}\sqrt[]{8})^2 \end{gathered}[/tex]Collect like terms:
[tex]\begin{gathered} =\text{ 36 }-\text{ 8} \\ =\text{ 28} \end{gathered}[/tex]Answer: 28
